<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2021-11-05</periodOfReport>

    <dateOfOriginalSubmission>2021-11-09</dateOfOriginalSubmission>

    <notSubjectToSection16>false</notSubjectToSection16>

    <issuer>
        <issuerCik>0001846069</issuerCik>
        <issuerName>Nextdoor Holdings, Inc.</issuerName>
        <issuerTradingSymbol>KIND</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001218352</rptOwnerCik>
            <rptOwnerName>KILGORE LESLIE J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O NEXTDOOR HOLDINGS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>420 TAYLOR STREET</rptOwnerStreet2>
            <rptOwnerCity>SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94102</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>true</isDirector>
            <isOfficer>false</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Class B Common Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2021-11-05</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>false</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>613758.00</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>613758.00</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>613758.00</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By The JLK Family Legacy Trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Class B Common Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2021-11-05</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>false</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>106577.00</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>106577.00</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>106577.00</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By the JLK Revocable Trust dtd October 13, 2003</value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares of Class B Common Stock received pursuant to a business combination (the &quot;Business Combination&quot;) which was effectuated in accordance with the terms of an Agreement and Plan of Merger dated as of July 6, 2021, entered into by and among: (i) Khosla Ventures Acquisition Co. II (the &quot;Issuer&quot;), a Delaware corporation; (ii) Lorelei Merger Sub Inc., a Delaware corporation and a wholly-owned subsidiary of the Issuer; and (iii) Nextdoor, Inc. (&quot;Original Nextdoor&quot;), a Delaware corporation. As a result of the Business Combination, Original Nextdoor became a wholly-owned subsidiary of the Issuer and the Issuer was renamed &quot;Nextdoor Holdings, Inc.&quot; Upon completion of the Business
Combination, the reporting person's shares of the capital stock of Original Nextdoor were exchanged for shares of Class B Common Stock of the Issuer based on an exchange ratio of approximately 3.1057 to 1.</footnote>
        <footnote id="F2">Each share of Class B Common Stock is convertible into one share of the Issuer's Class A Common Stock at the election of the holder at any
time; provided; however, that each share of Class B Common Stock shall automatically be converted into Class A Common Stock on a one-for-one
basis on the earlier of the: (i) tenth anniversary of completion of the Business Combination or (ii) date specified by the affirmative vote of the
holders of two-thirds of the Class B Common Stock then outstanding. In addition, each share of Class B Common Stock will convert automatically into one share of Class A Common Stock upon any transfer, whether or not for value (subject to certain exceptions).</footnote>
        <footnote id="F3">Certain of the shares are subject to the Issuer's right of repurchase if underlying vesting conditions are not met.</footnote>
    </footnotes>

    <remarks>This Form 4 is being amended to correct the total number of shares of Class B Common Stock owned by The JLK Family Legacy Trust. This amendment supersedes and replaces all prior amendments of this Form 4 previously filed.</remarks>

    <ownerSignature>
        <signatureName>/s/ Sophia Contreras Schwartz, as Attorney-in-Fact for Reporting Person</signatureName>
        <signatureDate>2022-04-07</signatureDate>
    </ownerSignature>
</ownershipDocument>
