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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-01-03</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001701114</issuerCik>
        <issuerName>Blue Apron Holdings, Inc.</issuerName>
        <issuerTradingSymbol>APRN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001136845</rptOwnerCik>
            <rptOwnerName>HUEBNER ELIZABETH</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O BLUE APRON HOLDINGS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>28 LIBERTY STREET</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10005</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2020-01-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>9709</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>9709</value>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>9709</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each restricted stock unit (&quot;RSU&quot;) represents a contingent right to receive one share of Class A Common Stock.</footnote>
        <footnote id="F2">Pursuant to the Company's non-employee director compensation policy, each new non-employee director is automatically granted, upon his or her initial appointment to the Board of Directors, a restricted stock unit award (&quot;Initial RSU Award&quot;) with an aggregate fair market value of $125,000, prorated for the number of days between the date of the director's initial appointment to the Board of Directors and the date of the next annual meeting of stockholders.  The date of the 2020 annual meeting of stockholders (the &quot;2020 Annual Meeting&quot;) has not yet been set.  The number of shares subject to Ms. Huebner's Initial RSU Award set forth above is based on the assumption that the 2020 Annual Meeting will be held on June 15, 2020, which is the first business day after the anniversary of the 2019 annual meeting of stockholders.  If the date of the 2020 Annual Meeting is different than June 15, 2020, the number of shares subject to Ms. Huebner's Initial RSU Award will be adjusted.</footnote>
        <footnote id="F3">The RSUs are scheduled to vest in full on the one-year anniversary of January 3, 2020.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Meredith Deutsch, as attorney-in-fact for Elizabeth Huebner</signatureName>
        <signatureDate>2020-01-07</signatureDate>
    </ownerSignature>
</ownershipDocument>
