Document And Entity Information Expected dividend yield Other income (expense): Note To Financial Statement Details Textual Significant Accounting Policies Note 2 - Summary of Significant Accounting Policies Note 4 - Debt Obligations Risk free interest rate Note 5 - Share-based Compensation Note 6 - Warrants Note 7 - Accounts Payable and Accrued Expenses Note 8 - Noncontrolling Interest - Clyra Medical Long-term liabilities: Employee Retention Program [Member] Related to employee retention program. Note 11 - Business Segment Information Note 12 - Leases Note 2 - Summary of Significant Accounting Policies - Summary of Cash Balances (Details) Note 2 - Summary of Significant Accounting Policies - Credit Concentration (Details) Term Loan Agreement [Member] The term loan agreement with American Express. Note 2 - Summary of Significant Accounting Policies - Inventory (Details) Expected volatility Note 2 - Summary of Significant Accounting Policies - Other Non-current Assets (Details) us-gaap_LiabilitiesCurrent Liabilities, Current Total current liabilities Note 2 - Summary of Significant Accounting Policies - Stock Options, Valuation Assumptions (Details) Warrant Holder Unit Offering [Member] The unit offering to warrant holders. Interest receivable Note 2 - Summary of Significant Accounting Policies - Schedule of Equipment and Leasehold Improvements (Details) Schedule of Debt [Table Text Block] Note 4 - Debt Obligations - Schedule of Debt (Details) Note 5 - Share-based Compensation - Stock Options (Details) Expected life in years (Year) Note 6 - Warrants - Warrants Outstanding (Details) Note 6 - Warrants - Assumptions Used to Determine Fair Value of Warrants (Details) Note 7 - Accounts Payable and Accrued Expenses - Summary of Accounts Payable and Accrued Expenses (Details) Proceeds from note receivable Note 8 - Noncontrolling Interest - Clyra Medical - Common Shares Outstanding (Details) Note 8 - Noncontrolling Interest - Clyra Medical - Valuation Assumptions (Details) Note 8 - Noncontrolling Interest - Clyra Medical - Warrants Outstanding (Details) Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Note 8 - Noncontrolling Interest - Clyra Medical - Summary of Accounts Payable and Accrued Expenses (Details) Aggregate intrinsic Value, Balance Note 8 - Noncontrolling Interest - Clyra Medical - Schedule of Lease Maturity (Details) Note 11 - Business Segment Information - Segment Information (Details) Note 12 - Leases - Schedule of Future Minimum Lease Payments (Details) Notes To Financial Statements Share-Based Payment Arrangement, Option, Activity [Table Text Block] Notes To Financial Statements [Abstract] Foreign currency translation (unaudited) Foreign currency translation (unaudited) Weighted average remaining term, Vested (Year) us-gaap_DebtCurrent Total current portion of debt us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1 Weighted average remaining term, balance (Year) Warrant exercise (unaudited) Represents the value of warrant exercise. Debt obligations Long-term debt, current Valuation Technique, Black-Scholes-Merton Model [Member] blgo_NumberOfPatentsAcquired Number of Patents Acquired Represents the number of patents acquired for the company. Options outstanding, Vested (in shares) Vested balance (in shares) Weighted average exercise price, Vested (in dollars per share) Weighted average exercise price, Vested (in dollars per share) blgo_ProceedsFromIssuanceOfCommonStockGross Proceeds From Issuance of Common Stock, Gross Represents the gross proceeds from the issuance of common stock. Aggregate intrinsic value, Vested us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Exercise Price (in dollars per share) us-gaap_NotesPayableCurrent Notes payable, current Board of Directors, Employees, and Consultants [Member] Represents the board of directors, employees, and consultants. us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest Total stockholders’ equity Balance Balance Weighted average remaining term, Outstanding (Year) Weighted average remaining term, balance (Year) Aggregate intrinsic value, balance Weighted average exercise price per share, unvested (in dollars per share) Weighted average price, Unvested (in dollars per share) Clyra options outstanding, Unvested (in shares) Unvested (in shares) Financial Asset, Past Due [Member] Financial Instruments [Domain] us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice Weighted average exercise price, balance (in dollars per share) Weighted average exercise price, balance (in dollars per share) Accounts payable and accrued expenses us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent Total Weighted average exercise price per share, Expired (in dollars per share) Financial Instrument [Axis] Weighted average exercise price, Granted (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share) blgo_WarrantsOutstandingWeightedAveragePricePerShare Outstanding Warrants, Weighted Average Price Per Share (in dollars per share) Outstanding Warrants, Weighted Average Price Per Share (in dollars per share) Represents the weighted average price per share for outstanding warrants. Weighted average exercise price, Exercised (in dollars per share) Lessor, Operating Leases [Text Block] Accrued payroll Accrued dividend Accounts payable Granted Warrants, Weighted Average Price Per Share (in dollars per share) Represents the weighted average exercise price of warrants granted. Revolving Credit Facility [Member] us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber Options outstanding, balance (in shares) Options outstanding, balance (in shares) Granted warrants, balance (in shares) Represents the warrants granted in period. us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod Options outstanding, Expired (in shares) Credit Facility [Axis] us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment Proceeds from Sale of Property, Plant, and Equipment Credit Facility [Domain] BEST [Member] Represents the B.E.S.T. reporting segment. us-gaap_PolicyTextBlockAbstract Accounting Policies Conversion of BETI Common Stock to BioLargo Common Stock [Member] Represents the conversion of BETI common stock into Biolargo Common Stock. us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares) blgo_LesseeOperatingLeaseLiabilityToBePaidAfterYearFour Thereafter Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in after the fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period (Year) us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares) us-gaap_PaymentsToAcquireMachineryAndEquipment Equipment purchases Warrants Outstanding for Noncontrolling Interest [Table Text Block] Represents the tabular disclosure for warrants outstanding from noncontrolling interests. us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1 Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) Clyra Medical Technologies [Member] Related to the entity Clyra Medical Technologies. Current liabilities: Operating lease liabilities us-gaap_IncreaseDecreaseInOperatingLeaseLiability Product [Member] Warrant In Connection With Convertible Note [Member] Represents warrant in connection with convertible note. Supplemental disclosures of cash flow information us-gaap_Assets Total assets Patents [Member] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Plan Name [Axis] blgo_FinitelivedTangibleAssetsNet Tangible assets Amount after amortization of assets which have physical substance with a finite life. BLEST [Member] Related to the entity BLEST. Plan Name [Domain] Compensation and Employee Benefit Plans [Text Block] us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount us-gaap_OperatingLeaseExpense Operating Lease, Expense Deposits Customer Deposit Liability, Current Amount of customer deposit liability, classified as current. us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1 Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year) us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic Net loss attributable to common shareholders BioLargo/ONM Lease [Member] Information related to the BioLargo/ONM lease. us-gaap_LossContingencyDamagesSoughtValue Loss Contingency, Damages Sought, Value Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] us-gaap_PreferredStockDividendsAndOtherAdjustments Preferred Stock Dividends and Other Adjustments Tomorrow Water [Member] Represents Tomorrow Water. BLEST Lease [Member] Information related to the BLEST lease. BKT and Tomorrow Water [Member] Represents BKT and Tomorrow Water. Award Type [Domain] us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders Clyra Medical dividend Series A Preferred stock (unaudited) Odin Co Ltd [Member] Represents Odin Co. Ltd. Award Type [Axis] us-gaap_IntangibleAssetsNetExcludingGoodwill Intangible Assets, Net (Excluding Goodwill), Total Investment in South Korean Joint Venture [Member] Represents information related to investment in South Korean joint venture. Net loss attributable to noncontrolling interest blgo_SharebasedCompensationArrangementBySharebasedPaymentAwardNumberOfAdditionalSharesAuthorizedPerYear Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized Per Year (in shares) Represents the number of additional shares authorized per year for issuance under an established share-based compensation plan. Share-Based Payment Arrangement, Option [Member] Warrant [Member] Loss Contingency, Nature [Domain] Odor-No-More [Member] Information pertaining to the operating segment of Odor-No-More. Clyra Segment [Member] Information pertaining to the operating segment of Clyra. Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Financial Asset, Aging [Axis] Financial Asset, Aging [Domain] Loss Contingency Nature [Axis] Comprehensive loss attributable to noncontrolling interest us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment Less: accumulated depreciation Equipment and leasehold improvements, net Total equipment and leasehold improvements, net Clyra Medical stock issued for services (unaudited) Clyra Medical stock unit offering (unaudited) Total, at cost Long-Term Debt, Type [Axis] Long-Term Debt, Type [Domain] us-gaap_NotesReceivableGross Financing Receivable, before Allowance for Credit Loss PPP loan forgiveness PPP loan forgiveness Represents the amount of gain recognized during the period from Paycheck Protection Program (CARES Act) loan forgiveness. Net loss Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net loss us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest Comprehensive loss Net loss (unaudited) blgo_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodFairValue Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Fair Value Fair value of options granted during the period. Excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock. Cash flows from investing activities Net loss per share attributable to common shareholders: us-gaap_ExtinguishmentOfDebtAmount Extinguishment of Debt, Amount Convertible Debt [Member] us-gaap_VariableInterestEntityOwnershipPercentage Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage us-gaap_IncomeLossFromEquityMethodInvestments Income (Loss) from Equity Method Investments (Gain) loss on investment in South Korean joint venture Accounts payable and accrued expenses us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities Investment in South Korean joint venture CANADA Notes Payable, Other Payables [Member] us-gaap_OperatingExpenses Total operating expenses us-gaap_DebtInstrumentTerm Debt Instrument, Term (Year) BETI Common Stock [Member] Represents BETI common stock. Exchange of BETI stock for BioLargo common stock (unaudited) (in shares) The number of shares exchanged for shares of noncontrolling interest during the period. blgo_StockConversionDiscountOnVolumeWeightedAveragePrice Stock Conversion, Discount on Volume Weighted Average Price Percentage discount on volume weighed average price upon conversion of stock. Cash and cash equivalents Cash and Cash Equivalent us-gaap_InterestExpenseNonoperating Interest expense Vehicle Loan [Member] Represents vehicle loan. blgo_PreferredStockConvertibleSaleOfStockAmount Preferred Stock, Convertible, Sale of Stock Amount Amount of proceeds in sale of stock for preferred stock to be convertible. us-gaap_DebtInstrumentConvertibleConversionPrice1 Debt Instrument, Convertible, Conversion Price (in dollars per share) us-gaap_AllocatedShareBasedCompensationExpense Share-Based Payment Arrangement, Expense Economic Injury Disaster Loan [Member] Related to debt under the SBA's Economic Injury Disaster Loan program. Amendment Flag Comprehensive loss: us-gaap_ComprehensiveIncomeNetOfTax Comprehensive loss attributable to common stockholders City Area Code Use of Estimates, Policy [Policy Text Block] us-gaap_DebtInstrumentPeriodicPayment Debt Instrument, Periodic Payment New Accounting Pronouncements, Policy [Policy Text Block] us-gaap_SharesOutstanding Shares, Outstanding (in shares) Contract liabilities us-gaap_IncreaseDecreaseInContractWithCustomerLiability Convertible Preferred Stock, Shares Outstanding (in shares) Current Fiscal Year End Date Consolidation, Subsidiaries or Other Investments, Consolidated Entities, Policy [Policy Text Block] us-gaap_DebtInstrumentInterestRateStatedPercentage Debt Instrument, Interest Rate, Stated Percentage us-gaap_NotesReceivableNet Financing Receivable, after Allowance for Credit Loss Paycheck Protection Program CARES Act [Member] Represents loan designed to provide funds for small businesses to keep their employees on the payroll. us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets Prepaid expenses and other assets us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent Operating Lease, Weighted Average Discount Rate, Percent Document Fiscal Period Focus us-gaap_IncreaseDecreaseInDepositOtherAssets Deposits Document Fiscal Year Focus Consolidation, Policy [Policy Text Block] blgo_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsDiscountRate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Discount Rate The discount rate assumption that is used in valuing an option on its own shares. Allocation of noncontrolling interest The amount of stock option expense allocated within noncontrolling itnerest. Noncontrolling interest allocation (unaudited) This element represents movements included in the statement of changes in stockholders' equity in connection with the allocation of noncontrolling interest from subsidiary's equity issuance. Document Period End Date Clyra Medical right-of-use asset and operating lease liability us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1 Operating Lease, Weighted Average Remaining Lease Term (Year) us-gaap_DebtLongtermAndShorttermCombinedAmount Total Entity File Number Entity Emerging Growth Company us-gaap_DebtInstrumentFaceAmount Debt Instrument, Face Amount Document Type Entity Small Business Entity Shell Company Document Information [Line Items] Document Information [Table] Service [Member] Entity Filer Category Debt Instrument [Axis] us-gaap_InvestmentOwnedBalanceShares Investment Owned, Balance, Shares (in shares) Entity Current Reporting Status Debt Instrument, Name [Domain] Schedule of Long-Term Debt Instruments [Table] us-gaap_IncreaseDecreaseInAccountsReceivable Accounts receivable Clyra Medical Common Stock [Member] Represents information related to Clyra Medical common stock. Credit concentration Entity Tax Identification Number Entity Central Index Key Entity Registrant Name Stock option compensation expense (unaudited) Entity [Domain] Customer Concentration Risk [Member] Legal Entity [Axis] Entity Address, Address Line One Offering Cost ecd_NonRule10b51ArrTrmntdFlag Non-Rule 10b5-1 Arrangement Terminated [Flag] Entity Address, City or Town ecd_Rule10b51ArrTrmntdFlag Rule 10b5-1 Arrangement Terminated [Flag] ecd_Rule10b51ArrAdoptedFlag Rule 10b5-1 Arrangement Adopted [Flag] Entity Address, Postal Zip Code Entity Address, State or Province Concentration Risk Type [Axis] ecd_NonRule10b51ArrAdoptedFlag Non-Rule 10b5-1 Arrangement Adopted [Flag] Concentration Risk Type [Domain] Material Terms of Trading Arrangement [Text Block] Entity Common Stock, Shares Outstanding Warrant Policy [Policy Text Block] Disclosure of accounting policy for warrant. Trading Arrangements, by Individual [Table] Accounts Receivable [Member] Investments [Domain] blgo_SubsidiaryParentOwnershipInterest Subsidiary, Parent Ownership Interest The percentage ownership interest of a subsidiary owned by the parent. Revenue from Contract with Customer Benchmark [Member] us-gaap_IncreaseDecreaseInInventories Inventories Trading Symbol Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Domain] Investment Type [Axis] Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Local Phone Number Stock option exercise (unaudited) (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period (in shares) Options Outstanding, Exercised (in shares) us-gaap_TableTextBlock Notes Tables us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity Line of Credit Facility, Maximum Borrowing Capacity Stock option exercise (unaudited) Selling, general and administrative expenses Bad debt expense Options outstanding, Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares) Warrant assumptions us-gaap_WarrantsAndRightsOutstandingMeasurementInput Warrants and Rights Outstanding, Measurement Input us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod Options outstanding, Expired (in shares) us-gaap_WarrantsAndRightsOutstandingTerm Warrants and Rights Outstanding, Term (Month) Line of Credit Facility, Lender [Domain] Sale of common stock for cash, net of offering costs (in shares) Stock Issued During Period, Shares, New Issues (in shares) Stock for service Clyra (unaudited) Issuance of common stock for services (unaudited) Stock Issued During Period, Value, Issued for Services Raw material Issuance of common stock for services (unaudited) (in shares) Stock Issued During Period, Shares, Issued for Services (in shares) Lender Name [Axis] us-gaap_LiabilitiesAndStockholdersEquity Total liabilities and stockholders’ equity Finished goods Sale of stock for cash, net of offering costs Common stock offering costs Non-Qualified Stock Option [Member] Represents the non-qualified stock option granted pursuant to the employment agreement. Accumulated deficit Research and development Research and development expense Accumulated other comprehensive loss Debt Disclosure [Text Block] us-gaap_InterestExpenseDebt Interest Expense, Debt Measurement Input, Price Volatility [Member] Changes in assets and liabilities: Measurement Input, Risk Free Interest Rate [Member] us-gaap_DisclosureTextBlockAbstract Notes to Financial Statements Subsequent Event [Member] Schedule of Cash and Cash Equivalents [Table Text Block] Measurement Input, Expected Dividend Rate [Member] Operating lease liabilities, net of current Schedule of Inventory, Current [Table Text Block] Measurement Input, Expected Term [Member] Total operating lease liabilities Operating Lease, Liability Subsequent Event [Table] Subsequent Event Type [Axis] Operating lease liabilities Subsequent Event Type [Domain] Finance lease liability Exchange of BETI stock for BioLargo common stock (unaudited) Represents the value of the stock issued during the period that is exchanged for noncontrolling interest. Finance lease liability, net of current Subsequent Events [Text Block] blgo_GrantTerm Grant Term (Month) Period for grants earned during the period from non-repayable sum of money awarded to an entity to carry out a specific purpose as provided in grant agreements. Operating lease right-of use Operating lease right-of-use assets, net Operating Lease, Right-of-Use Asset us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue Lessee, Operating Lease, Liability, to be Paid Total minimum lease payments SBA EIDL Loan [Member] SBA EIDL Loan us-gaap_FinanceLeaseLiability Finance Lease, Liability us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount Less imputed interest Measurement Input Type [Axis] December 31, 2028 Canadian Government Grants [Member] The Canadian National Research Institute – Industrial Research Assistance Program (NRC-IRAP) and the National Science and Engineering Research Council of Canada (NSERC). Measurement Input Type [Domain] December 31, 2029 Finance lease right-of-use Financing lease right-of-use asset, net Finance Lease, Right-of-Use Asset, after Accumulated Amortization Fair Value of Financial Instruments, Policy [Policy Text Block] Vendor Warrants [Member] Vendor Warrants December 31, 2026 December 31, 2027 Valuation Approach and Technique [Axis] Valuation Approach and Technique [Domain] Warrants Issued in October 2025 Offering [Member] Warrants Issued in October 2025 Offering Warrant in Connection with Guaranteed Note [Member] Warrant in Connection with Guaranteed Note Consultants and Vendors [Member] Consultants and Vendors Common stock issued for services Equity-Based Arrangements, Individual Contracts, Type of Deferred Compensation [Domain] blgo_NumberOfReportableSegmentsNotDisclosedFlag Number of Reportable Segments Not Disclosed [Flag] us-gaap_StockOptionPlanExpense Stock option expense Foreign Currency Transactions and Translations Policy [Policy Text Block] Consultants [Member] Represents the Consultants. Conversion of BETI Stock into BioLargo Stock [Member] Conversion of BETI Stock into BioLargo Stock Conversion of Clyra note payable into Clyra shares Debt Conversion, Converted Instrument, Amount Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block] Other non-current assets Total Stock option compensation expense us-gaap_ShareBasedCompensation Lessee, Leases [Policy Text Block] us-gaap_DebtConversionConvertedInstrumentSharesIssued1 Debt Conversion, Converted Instrument, Shares Issued (in shares) Clyra Office Lease [Member] Clyra Office Lease December 31, 2025 Equity-Based Arrangements, Individual Contracts, Type of Deferred Compensation [Axis] Earnings Per Share, Policy [Policy Text Block] Amortization of debt discount Credit loss expense Represents amount of credit loss expense. Non Cash Transactions [Policy Text Block] Accounting policy disclosure for non cash transactions. Debt Conversion Description [Axis] Schedule of Other Ownership Interests [Table Text Block] Note receivable, net of current Debt Conversion, Name [Domain] Clyra Medical Preferred Stock, Series B [Member] Clyra Medical Preferred Stock, Series B Income Tax, Policy [Policy Text Block] 2024 Equity Incentive Plan [Member] Represents the information pertaining to 2024 equity incentive plan. us-gaap_LesseeOperatingLeaseTermOfContract Lessee, Operating Lease, Term of Contract (Year) Conversion of BETI common stock to BioLargo common stock Depreciation expense Depreciation us-gaap_ConversionOfStockSharesIssued1 Conversion of Stock, Shares Issued (in shares) us-gaap_ConversionOfStockSharesConverted1 Conversion of Stock, Shares Converted (in shares) Warrants [Text Block] Disclosure of notes that entitle the holder to buy stock of the company at a specified price, which is much higher than the stock price at the time of issue. us-gaap_SharesIssued Shares, Issued (in shares) Balance (in shares) Balance (in shares) blgo_PercentageOfProfitsInterestsVested Percentage of Profits Interests Vested Represents percentage of profits interest vested. us-gaap_SharesIssuedPricePerShare Shares Issued, Price Per Share (in dollars per share) Stock Conversion Description [Axis] Conversion of Stock, Name [Domain] us-gaap_AssetsCurrent Assets, Current Total current assets Share-Based Payment Arrangement [Policy Text Block] blgo_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsGrantsInPeriodGrossPerMonth Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross, Per Month (in shares) Gross number of share options (or share units) granted during period per month. Warrant exercise (unaudited) blgo_StockIssuedDuringPeriodValueExerciseOfWarrants The value of stock issued during the period as a result of warrant exercises. Warrant exercise (unaudited) (in shares) blgo_StockIssuedDuringPeriodSharesExerciseOfWarrants Shares issued during the period as a result of warrant exercises. Clyra Medical fair value warrant issued with debt (unaudited) Amount of increase in noncontrolling interest from warrants issued. Weighted average price, Granted (in dollars per share) Per share or per unit price of warrants or rights issued during the period. blgo_ClassOfWarrantOrRightExercisedDuringPeriod Class of Warrant or Right, Exercised During Period (in shares) Warrants outstanding, Exercised (in shares) The number of warrants exercised during the period. us-gaap_LesseeFinanceLeaseTermOfContract1 Lessee, Finance Lease, Term of Contract (Year) Weighted average price, Exercised (in dollars per share) Per share or per unit price of warrant or right exercised in period. Schedule Of Assumptions Used To Determine Fair Value Of Warrants [Table Text Block] The tabular disclosure of assumptions used to determine the fair value of warrants. Patents The value of patents classified as noncurrent. Security deposits The amount of security deposits classified as noncurrent. Common stock, $0.00067 Par Value, 550,000,000 Shares Authorized, 311,452,683 and 301,274,243 Shares Issued, at September 30, 2025 and December 31, 2024 Equity Incentive Plan 2007 [Member] Equity incentive plan 2007 member. Adjustments to reconcile net loss to net cash used in operating activities: Common stock, shares authorized (in shares) Common stock, shares issued (in shares) us-gaap_LesseeOperatingLeaseDiscountRate Lessee, Operating Lease, Discount Rate Common stock, par value (in dollars per share) Statistical Measurement [Domain] Lessee, Lease, Description [Table] Maximum [Member] Non-cash investing and financing activities Minimum [Member] Weighted Average [Member] Ownership [Domain] Employees [Member] Represents the employees. Product and Service [Axis] Product and Service [Domain] Statistical Measurement [Axis] us-gaap_FinanceLeaseInterestPaymentOnLiability Finance lease liability Investment, Name [Domain] Litigation Case [Axis] Litigation Case [Domain] Ownership [Axis] Preferred Series A, $0.00067 Par Value, 50,000,000 Shares Authorized, no Shares Issued and Outstanding, at September 30, 2025 and December 31, 2024 Convertible Preferred Stock, Shares Issued (in shares) Interest Income taxes Investment, Name [Axis] Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block] Customer A [Member] Refers to information regarding customer A. Geographical [Axis] Geographical [Domain] blgo_NumberofAccreditedInvestors Number of Accredited Investors Number of accredited investors. Property, Plant and Equipment [Table Text Block] Convertible Preferred Stock, Shares Authorized (in shares) Weighted average price, Expired (in dollars per share) Per share or per unit price of warrants or rights expired during the period. Inventories Total Convertible Preferred Stock, Par Value (in dollars per share) Customer B [Member] Refers to information regarding customer B. Non Plan [Member] Represents the absence of a plan. us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax Revenue from Contract with Customer, Including Assessed Tax us-gaap_InventoryValuationReserves Inventory Valuation Reserves Conversion of Debt into Shares of Common Stock [Member] Represents the conversion of debt into shares of common stock. Warrants Issued in Conjunction With the Sale of Series A Preferred Stock [Member] Represents Warrants Issued in Conjunction With the Sale of Series A Preferred Stock. Clyra Medical [Member] Related to the entity Clyra Medical. Customer [Axis] Entities, Excluding Partially Owned Subsidiary [Member] Represents all the consolidated entities, excluding partially owned subsidiary. Customer [Domain] blgo_WarrantsAndRightsOutstandingFairValue Warrants and Rights Outstanding, Fair Value Represents fair value of warrants and rights. us-gaap_ProvisionForLoanLeaseAndOtherLosses Provision for Loan, Lease, and Other Losses Partially Owned Subsidiary [Member] Represents the partially owned subsidiary. Royalty Receivable [Member] Represents Royalty Receivable. us-gaap_PropertyPlantAndEquipmentUsefulLife Property, Plant and Equipment, Useful Life (Year) us-gaap_InterestIncomeExpenseNet Interest income (expense) Product Invoice Receivable [Member] Represents product invoice receivable. us-gaap_PreferredStockDividendRatePercentage Preferred Stock, Dividend Rate, Percentage Non-controlling interest (Notes 8, 9, 10) blgo_EngagementExtensionTerm Engagement Extension, Term (Year) Represents duration term of engagement extension. Clyra Medical stock option compensation expense (unaudited) Amount of increase in additional paid in capital from subsidiary issuance of equity interests for service. Cash flows from operating activities Schedule of Segment Reporting Information, by Segment [Table Text Block] Schedule of Segment Reporting Information, by Segment [Table] Revenue [Policy Text Block] Balance, aggregate intrinsic value Warrants and Rights Outstanding Vendors [Member] The element represents vendors. Statement [Line Items] Collectability of Royalty Receivables [Member] The assets of an enterprise may include receivables that arose from royalty. us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent Accounts Receivable, Allowance for Credit Loss, Current Lawsuit Against Pooph Inc. 8:25-cv-02516 [Member] Represents Lawsuit Against Pooph Inc. case number 8:25-cv-02516. us-gaap_NumberOfOperatingSegments Number of Operating Segments Accounts receivable, net of allowances Collectability of Product Invoice Receivables [Member] The assets of an enterprise may include receivables that arose from product invoice. Additional paid-in capital Revenue AOCI Attributable to Parent [Member] blgo_WorkingCapitalDeficit Working Capital (Deficit) Represents the value of total current assets net of current liabilities as of the balance sheet date. Leasehold Improvements [Member] Property, Plant and Equipment, Policy [Policy Text Block] Long-Lived Tangible Asset [Axis] Amortization of right-of-use finance lease asset Represents The increase (decrease) during the reporting period in right of use and lease liability, net us-gaap_NonoperatingIncomeExpense Total other expense Segment Reporting Disclosure [Text Block] Long-Lived Tangible Asset [Domain] Chief Financial Officer [Member] Current assets: Schedule of Other Assets, Noncurrent [Table Text Block] us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations Cash and cash equivalents at beginning of period Cash and cash equivalents at end of period Inventory, Policy [Policy Text Block] Interest income Investment Income, Interest Net effect of foreign currency translation us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect Net change in cash us-gaap_NetCashProvidedByUsedInFinancingActivities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Net cash provided by financing activities us-gaap_Liabilities Total liabilities Sale of Stock [Axis] Director [Member] Sale of Stock [Domain] Operating income (loss) Operating loss: us-gaap_NetCashProvidedByUsedInOperatingActivities Net cash used in operating activities us-gaap_NetCashProvidedByUsedInInvestingActivities Net cash provided by (used in) investing activities Prepaid expenses and other current assets us-gaap_GrossProfit Gross profit Consolidation, Eliminations [Member] us-gaap_CostOfGoodsAndServicesSold Cost of Goods and Services Sold Counterparty Name [Axis] Government Grants [Policy Text Block] The disclosure of policies relating to government grants. Counterparty Name [Domain] Employees and Consultants [Member] Employees and Consultants. Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block] us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations Cash Provided by (Used in) Operating Activity, Discontinued Operation Consolidation Items [Domain] Short-term lease payments not included in lease liabilities Noncash short-term lease payments not included in lease liability. STOCKHOLDERS’ EQUITY: Sale Leaseback Transaction, Name [Domain] Consolidation Items [Axis] Parent Company [Member] Total blgo_TangibleAndIntangibleAssetsRightofuseAssetsAndEquityMethodInvestmentTotal Total amount of tangible and intangible assets, right-of-use assets and equity method investment. Sale Leaseback Transaction, Description [Axis] blgo_DebtInstrumentPercentageOfPrincipalPaymentCap Debt Instrument, Percentage of Principal Payment, Cap Represents the maximum percentage of principal due monthly. Consolidated Entities [Axis] Equity Method Investments [Policy Text Block] Consolidated Entities [Domain] Concentration Risk, Credit Risk, Policy [Policy Text Block] Warrants Issued in Connection with Conversion of Interest on Note Payable Maturing March 8, 2023 [Member] Represents the warrants issued in connection with conversion of interest on note payable maturing March 8, 2023. Officer [Member] blgo_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsGrantsInPeriodGrossUponRenewal Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Available Grants in Period, Gross, Upon Renewal (in shares) Gross number of share options (or share units) available to be granted during the period upon renewal of the option. Warrants Issued Concurrently with Note Payable [Member] Refers to information regarding warrants issued concurrently with Note Payable. BioLargo Energy Technologies, Inc (BETI) [Member] Information pertaining to BioLargo Energy Technologies, Inc. (BETI). blgo_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestingPeriodForRenewableOptions Share-based Compensation Arrangement by Share-based Payment Award, Options, Vesting Period for Renewable Options (Year) The vesting period for renewable options from a share-based compensation arrangement. Cost of revenue BETI unit offering (unaudited) Value of the new units issued during the period. Each unit consists of a convertible promissory note and a stock purchase warrant. Noncontrolling Interest [Member] us-gaap_ProceedsFromIssuanceOrSaleOfEquity Proceeds from Issuance or Sale of Equity Proceeds from warrant exercise Proceeds from Warrant Exercises blgo_StockIssuedDuringPeriodSharesCashlessExerciseOfOptions Stock Issued During Period, Shares, Cashless Exercise of Options (in shares) The number of shares issued during the period for cashless exercise of options. March 31, 2025 Warrants [Member] Represents the warrants issued on March 31, 2025. Retained Earnings [Member] Proceeds from sale of common stock, net of commissions The cash inflow (outflow) from the additional capital contribution to the entity, net of commissions. Proceeds from option exercise Proceeds from BETI unit offering The cash inflow from the issuance of units during the period. Proceeds from sale of common stock Proceeds from Issuance of Common Stock Title and Position [Domain] Title and Position [Axis] blgo_ClassOfWarrantOrRightDiscountPercentage Class of Warrant or Right, Discount Percentage Percentage of discount on warrant or rights. Warrants Issued With Secured Promissory Notes and Convertible Promissory Notes [Member] Represents warrants issued with Secured Promissory Notes and Convertible Promissory Notes. Proceeds from Clyra Medical preferred series B Proceeds from Issuance of Preferred Stock and Preference Stock Additional Paid-in Capital [Member] Common Stock [Member] Sale of common stock for cash, net of offering costs Equity impact of the value of new stock issued during the period, net of offering costs. Equity Components [Axis] Equity Component [Domain] us-gaap_LongTermDebt Long-Term Debt Stock, Class of Stock [Table] Class of Financing Receivable [Domain] us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1 Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) Weighted average price, balance (in dollars per share) Weighted average price, balance (in dollars per share) Class of Warrant or Right [Axis] Class of Warrant or Right [Domain] us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares) Class of Financing Receivable [Axis] us-gaap_ClassOfWarrantOrRightOutstanding Warrants outstanding, balance (in shares) Warrants outstanding, balance (in shares) Class of Warrant or Right [Table] Vernal Bay Capital Group, LLC [Member] Information related to Vernal Bay Capital Group, LLC. Inventory Line of Credit [Member] Information related to the inventory line of credit. Warrant exercise (unaudited) (in shares) Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) ONM [Member] Related to ONM. Fair value of Clyra Medical warrants issued as debt discount Amount of fair value of warrants issued with note payable in noncash transaction. Grant income The amount of nonoperating income from grants. us-gaap_LineOfCredit Long-Term Line of Credit The Five Year Warrants Issued in Unit Offerings [Member] Represents the five year warrants issued in unit offerings. The Six Month Warrants Issued in Unit Offerings [Member] Represents the six month warrants issued in unit offering. Unit Offering [Member] Represents the Unit Offering. Replacement Options [Member] Represents replacement options. Equipment [Member] Accounts Receivable [Policy Text Block] Measurement Input, Forfeiture Rate [Member] Measurement input using forfeiture rate. Preferred Stock, Series A [Member] Represents Series A Preferred Stock. Debt Instrument, Unamortized Discount, Current Cash and Cash Equivalents, Policy [Policy Text Block] Debt Instrument, Unamortized Discount, Noncurrent Warrants Issued in Unit Offerings [Member] Represents warrants issued in unit offerings. blgo_ClassOfWarrantOrRightExpiredDuringPeriod Warrants outstanding, Expired (in shares) The number of warrants or rights expired during period. Document Quarterly Report Warrants outstanding, Granted (in shares) Class of Warrant or Right, Issued During Period (in shares) The number of warrants or rights issued during period. Entity Incorporation, State or Country Code us-gaap_UnrecognizedTaxBenefits Unrecognized Tax Benefits us-gaap_DebtInstrumentCarryingAmount Long-Term Debt, Gross Accounting Policies [Abstract] Significant Accounting Policies [Text Block] Document Transition Report Selling, General and Administrative Expenses [Member] Schedules of Concentration of Risk, by Risk Factor [Table Text Block] Entity Interactive Data Current Title of 12(b) Security Forfeiture rate Represents expected forfeiture rate for share-based payment awards. Proceeds from Clyra Medical debt obligations Weighted average remaining life, balance (Year) Weighted average remaining term for warrants outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Statement of Income Location, Balance [Axis] Statement of Income Location, Balance [Domain] blgo_NumberOfWhollyOwnedSubsidiaries Number of Wholly-Owned Subsidiaries Represents the number of wholly-owned subsidiaries operated by the company. blgo_NumberOfMajorCustomers Number of Major Customers Represents the number of major customers accounting for 10% or more of the specified concentration risk benchmark, which includes, but not limited to, sales revenue, accounts receivable, etc. The 2007 Equity Incentive Plan [Member] Represents information pertaining to the Company's 2007 Equity Incentive Plan. us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners Subsidiary, Ownership Percentage, Noncontrolling Owner Sale Leaseback of Equipment [Member] Relating to sale leaseback of equipment. blgo_LesseeFinanceLeasePurchaseOptionAmount Lessee, Finance Lease, Purchase Option, Amount Represents the amount of a purchase option on a finance lease. Segments [Axis] Segments [Domain] Exercised warrants, weighted average price per share (in dollars per share) Represents the weighted average exercise price of warrants exercised. Exercised warrants, balance (in shares) Represents the number of warrants exercised during the period. us-gaap_SharePrice Share Price (in dollars per share) Seven Employees Working at BioLargo Engineering, Science & Technologies, LLC [Member] Refers to information regarding seven employees working at BioLargo Engineering, Science & Technologies, LLC. us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares) us-gaap_RepaymentsOfLinesOfCredit Repayments of Lines of Credit Preferred Shares Issued for Debt Owed to Biolargo [Member] Represents preferred shares issued for debt owed to BioLargo. us-gaap_ProceedsFromLinesOfCredit Proceeds from Lines of Credit, Total 2018 Equity Incentive Plan [Member] Represents the information pertaining to 2018 equity incentive plan. BioLargo Canada [Member] Information pertaining to the operating segment BioLargo Canada. Noncontrolling Interest [Table] blgo_StockPurchaseAgreementMaximumAmountOfCommonStock Stock Purchase Agreement, Maximum Amount of Common Stock The maximum value available of the common stock for sale in a stock purchase agreement. Statement [Table] us-gaap_MinorityInterestOwnershipPercentageByParent Subsidiary, Ownership Percentage, Parent Statement of Financial Position [Abstract] Weighted average number of common shares outstanding: (in shares) Accounts Payable and Accrued Liabilities Disclosure [Text Block] Lincoln Park Capital Fund, LLC [Member] Refers to information regarding the entity Lincoln Park Capital Fund, LLC. Noncontrolling Interest Disclosure [Text Block] Loss per share attributable to shareholders – basic and diluted (in dollars per share) Credit Loss, Financial Instrument [Policy Text Block] Statement of Cash Flows [Abstract] Wholly-Owned Subsidiary [Text Block] The textual disclosure of a wholly-owned subsidiary. Statement of Stockholders' Equity [Abstract] BioLargo Engineering, Science & Technologies, LLC [Member] Refers to information regarding the entity BioLargo Engineering, Science & Technologies, LLC. Lease Contractual Term [Domain] Stock Purchase Agreement [Text Block] The textual disclosure of information pertaining to a stock purchase agreement. Lease Contractual Term [Axis] Income Statement [Abstract] Proceeds from debt obligation Proceeds from Issuance of Debt Debt Excluding Clyra Medical Technologies [Member] Represents debt excluding Clyra medical technologies. us-gaap_RepaymentsOfDebt Repayment of debt obligations Schedule of Accounts Payable and Accrued Liabilities [Table Text Block] us-gaap_FinanceLeaseLiabilityPaymentsDue Total minimum lease payments us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount Less imputed interest us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths December 31, 2026 us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo December 31, 2027 us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree December 31, 2028 us-gaap_ReceivableWithImputedInterestEffectiveYieldInterestRate Receivable with Imputed Interest, Effective Yield (Interest Rate) Accounting Standards Update and Change in Accounting Principle [Table] Offsetting Liabilities [Table] Other Assets, Policy [Policy Text Block] Disclosure of accounting policy for assets classified as other. Finance Lease, Liability, to be Paid, Maturity [Table Text Block] us-gaap_FinanceLeaseLiabilityPaymentsRemainderOfFiscalYear December 31, 2025 us-gaap_LiabilitiesNoncurrent Total long-term liabilities Cash flows from financing activities Clyra Medical dividend Series A Preferred stock Warrants Expiring February 28, 2027 [Member] Represents warrants expiring on February 28, 2027. Segment Reporting, Reconciling Item, Corporate Nonsegment [Member] Preferred Class A [Member] Series A Preferred Stock [Member] Series B Preferred Stock [Member] us-gaap_PaymentsToAcquireInterestInJointVenture Payments to Acquire Interest in Joint Venture Amortization of right-of-use operating lease assets us-gaap_StockholdersEquity Total BioLargo Inc. and subsidiaries stockholders’ equity Class of Stock [Axis] Class of Stock [Domain] Debt obligations, net of current Total long-term debt, net of current Clyra Medical Unit Warrant offering (unaudited) The amount of increase from the warrant offering. blgo_PolicyTable Conversion of accounts receivable to a note receivable The conversion of accounts receivable into notes receivable. Operating Segments [Member] Clyra conversion of note payable and interest (unaudited) Amount of increase in noncontrolling interest from conversion of notes payable and interest.