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

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2026-01-30</periodOfReport>

    <issuer>
        <issuerCik>0001766502</issuerCik>
        <issuerName>Chewy, Inc.</issuerName>
        <issuerTradingSymbol>CHWY</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001778095</rptOwnerCik>
            <rptOwnerName>Mehta Satish</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>7700 WEST SUNRISE BOULEVARD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PLANTATION</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33322</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>1</isOfficer>
            <officerTitle>Chief Technology Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>1</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2026-01-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>29243</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>30.14</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>273320</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2026-02-02</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>13013</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>28.99</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>273835</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>13528</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>162139</value>
                    <footnoteId id="F4"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>63447</value>
                    <footnoteId id="F5"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>62097</value>
                    <footnoteId id="F6"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares of Class A common stock of Chewy, Inc. that were withheld to satisfy tax withholding and remittance obligations in connection with the net settlement of vested restricted stock units (&quot;RSUs&quot;) and does not represent a market transaction. This transaction is exempt from Section 16(b) of the Securities Exchange Act of 1934, as amended, pursuant to Rule 16b-3(e) promulgated thereunder.</footnote>
        <footnote id="F2">Represents sales effected pursuant to a Rule 10b5-1 trading plan adopted by the filing person on September 23, 2025.</footnote>
        <footnote id="F3">Represents RSUs granted to the filing person on April 6, 2023. Each RSU represents a contingent right to receive one share of Class A common stock of Chewy, Inc. The RSUs are subject to time-vesting conditions. 50% will vest on August 1, 2026 and the remaining 50% will vest on February 1, 2027, subject to the filing person's continued employment with Chewy, Inc. through the applicable vesting date.</footnote>
        <footnote id="F4">Represents PRSUs granted to the filing person. Each PRSU represents a contingent right to receive one share of Class A common stock of Chewy, Inc. The PRSUs were initially granted on April 4, 2024 and the amount of PRSUs eligible for vesting was subject to certification of the satisfaction of certain performance conditions for the 2024 fiscal year by the Compensation Committee of the Board of Directors. On March 26, 2025, the Compensation Committee of the Board of Directors certified the achievement of the performance conditions for the PRSUs, which vest on February 1, 2027, subject to the filing person's continued employment with Chewy, Inc. through the vesting date.</footnote>
        <footnote id="F5">Represents RSUs granted to the filing person on April 4, 2024. Each RSU represents a contingent right to receive one share of Class A common stock of Chewy, Inc. The RSUs are subject to time-vesting conditions. 12.5% will vest on May 1, 2026 and on each three-month anniversary thereafter, subject to the filing person's continued employment with Chewy, Inc. through the applicable vesting date.</footnote>
        <footnote id="F6">Represents RSUs granted to the filing person on April 8, 2025. Each RSU represents a contingent right to receive one share of Class A common stock of Chewy, Inc. The RSUs are subject to time-vesting conditions. 25% of these RSUs will vest on March 1, 2026, and 6.25% will vest on each three-month anniversary thereafter, subject to the filing person's continued employment with Chewy, Inc. through the applicable vesting date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Da-Wai Hu, as Attorney-in-Fact for Satish Mehta</signatureName>
        <signatureDate>2026-02-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
