Basis of Presentation and Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) and applicable rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”) regarding interim financial reporting. Accordingly, they do not include all disclosures normally required in annual financial statements prepared in accordance with GAAP. Therefore, these unaudited condensed financial statements should be read in conjunction with the audited financial statements and notes for the year ended December 31, 2021 included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021, which was filed with the SEC on March 28, 2022. In management’s opinion, these unaudited condensed financial statements have been prepared on the same basis as the annual financial statements and reflect all adjustments, which include only normal recurring adjustments necessary for the fair statement of the Company’s financial position as of March 31, 2022, results of operations for the three months ended March 31, 2022 and 2021, cash flows for the three months ended March 31, 2022 and 2021, and stockholders' equity (deficit) for the three months ended March 31, 2022 and 2021. The results of operations for the three months ended March 31, 2022 and 2021 are not necessarily indicative of the results to be expected for the full year or any other future interim or annual period.
Segment Information	Segment Information The Company has a single operating and reportable segment. In reaching this conclusion, management considers the definition of the chief operating decision maker (“CODM”), how the business is defined by the CODM, the nature of the information provided to the CODM and how that information is used to make operating decisions, allocate resources and assess performance. The Company’s chief operating decision maker is its Chief Executive Officer, who reviews financial information presented on an aggregated basis for purposes of making operating decisions, assessing financial performance and allocating resources.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported and disclosed in the financial statements and the accompanying notes. Such estimates and assumptions include the costs to be capitalized as internal-use software and their useful life, the useful lives of other long-lived assets, impairment considerations for long-lived assets, the determination of the incremental borrowing rate for lease agreements, expected lease term, and lease and non-lease component allocation, estimates related to variable consideration, valuation of the Company’s common stock prior to our initial public offering in November 2021 (the “IPO”), stock options, and Employee Stock Purchase Plan and accounting for taxes, including estimates for sales tax and VAT liability, deferred tax assets, valuation allowance and uncertain tax positions. The Company bases its estimates on historical experience and on assumptions that management considers reasonable. Future actual results could differ materially from these estimates.
Concentrations	Concentrations Vendors. The Company acquires infrastructure equipment from third-party vendors. Vendors may have limited sources of equipment and supplies which may expose the Company to potential supply and service disruptions that could harm the Company’s business. Two vendors represented an aggregate 23% of total cash disbursements during the three months ended March 31, 2022, while three vendors represented an aggregate 38% of the accounts payable balance as of March 31, 2022. Two vendors represented in aggregate 29% of total cash disbursements during the three months ended March 31, 2021, while three vendors represented 40% of the accounts payable balance as of December 31, 2021. Revenue. The Company derives substantially all of its revenue from the services operating on its Backblaze Storage Cloud platform: its Backblaze B2 Cloud Storage (“Backblaze B2”) and Backblaze Computer Backup (“Computer Backup”) offerings. The potential for severe impact to the Company’s business could result if the Company was unable to operate its platform or serve customers through its platform for an extended period of time.
Accounting Pronouncements Recently and Not Yet Adopted	Accounting Pronouncements Recently Adopted In February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2016-02, Leases (Topic 842), and since that date, has issued several ASUs to further clarify certain aspects of ASU 2016-02 and provide entities with practical expedients that may be elected upon adoption. The Company adopted the new standard beginning January 1, 2022 using the modified retrospective approach, electing the optional transition approach of not adjusting the comparative period financial statements for the impact of adoption. The Company elected the package of practical expedients permitted under the transition guidance, which allows the Company to carryforward its historical lease classification, its assessment on whether a contract is or contains a lease, and its initial direct costs for any leases that existed prior to adoption of the new standard. In accordance with ASU 2016-02, the Company determines if an arrangement is a lease at its inception. Right-of-use (“ROU”) assets, and corresponding lease liabilities, are recognized at the commencement date based on the present value of remaining lease payments over the lease term, which, for the Company, include primarily fixed payments. As a majority of the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available as of the commencement date. For leases existing at adoption, the Company elected to use the remaining lease term and remaining minimum lease payments in calculating the incremental borrowing rate for all existing leases. The discount rate used is the rate of interest that a lessee would have to pay to borrow on a collateralized basis over a similar term an amount equal to the lease payments in a similar economic environment. The lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise such options. The Company has elected the short-term lease practical expedient for all asset classes, which allows the lessee to not apply the recognition requirements of Accounting Standards Codification (“ASC”) 842 to short-term leases (leases with original terms of 12 months or less and that do not include a purchase option that the lessee is reasonably certain to exercise). The Company has elected the practical expedient to combine lease and non-lease components for all of its leases, with the exception of its colocation lease agreement asset class. The adoption of the new standard on January 1, 2022 resulted in the recognition of approximately $5.2 million and $5.6 million of operating lease ROU assets and operating lease liabilities on the Company's condensed balance sheets, respectively, with the ROU asset on an existing lease being offset by an existing ASC 420 obligation of approximately $0.4 million. The Company noted no material impact on its condensed financial statements with respect to its finance leases as a result of its ASC 842 adoption. See Note 10 to these condensed financial statements Accounting Pronouncements Not Yet Adopted In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which requires a financial asset measured at amortized cost basis to be presented at the net amount expected to be collected, with further clarifications made more recently. For trade receivables, loans and other financial instruments, the Company will be required to use a forward-looking expected loss model rather than the incurred loss model for recognizing credit losses which reflects losses that are probable. Credit losses relating to available-for-sale debt securities are required to be recorded through an allowance for credit losses rather than as a reduction in the amortized cost basis of the securities. This guidance is effective for the Company for its fiscal year beginning January 1, 2023 and interim periods within that fiscal year. The Company is currently evaluating the impact of the adoption of this guidance on its financial statements.