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    <periodOfReport>2025-12-01</periodOfReport>

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    <issuer>
        <issuerCik>0001484778</issuerCik>
        <issuerName>ThredUp Inc.</issuerName>
        <issuerTradingSymbol>TDUP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001688472</rptOwnerCik>
            <rptOwnerName>Sobers Sean</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O THREDUP INC.</rptOwnerStreet1>
            <rptOwnerStreet2>969 BROADWAY, SUITE 200</rptOwnerStreet2>
            <rptOwnerCity>OAKLAND</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94607</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Financial Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

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                </transactionShares>
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        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
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                </underlyingSecurityTitle>
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    <footnotes>
        <footnote id="F1">Shares purchased pursuant to the ThredUp Inc. 2021 Employee Stock Purchase Plan.</footnote>
        <footnote id="F2">Represents the number of shares sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of RSUs. This sale is mandated by the Issuer's election under its equity incentive plans to require the satisfaction of tax withholding obligations to be funded by a &quot;sell to cover&quot; transaction and does not represent a discretionary trade by the Reporting Person.</footnote>
        <footnote id="F3">Each RSU represents a contingent right to receive one share of the Issuer's Class A Common Stock.</footnote>
        <footnote id="F4">On February 15, 2023, the Reporting Person was granted 443,495 RSUs, vesting in twelve equal quarterly installments on June 1, September 1, December 1 and March 1 until fully vested, subject to the Reporting Person's continued service to the Issuer on each such date.</footnote>
        <footnote id="F5">On February 26, 2024, the Reporting Person was granted 440,000 RSUs, vesting in twelve equal quarterly installments on June 1, September 1, December 1 and March 1 until fully vested, subject to the Reporting Person's continued service to the Issuer on each such date.</footnote>
        <footnote id="F6">On January 9, 2025, the Reporting Person was granted 310,000 RSUs, vesting in twelve equal quarterly installments on June 1, September 1, December 1 and March 1 until fully vested, subject to the Reporting Person's continued service to the Issuer on each such date.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Alon Rotem, Attorney-in-Fact</signatureName>
        <signatureDate>2025-12-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
