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

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-08-04</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>2025-08-04</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5967</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>35.5705</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>285194</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-08-05</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>8727</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>35.82</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>276467</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>64931</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>27056</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>162139</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>94235</value>
                    <footnoteId id="F6"/>
                </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="F7"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents &quot;sell to cover&quot; sales effected pursuant to a Rule 10b5-1 trading plan adopted by the filing person on April 15, 2022 to cover tax withholding obligations in connection with the vesting of restricted stock units (&quot;RSUs&quot;).</footnote>
        <footnote id="F2">Represents sales effected pursuant to a Rule 10b5-1 trading plan adopted by the filing person on April 9, 2025.</footnote>
        <footnote id="F3">Represents performance-based restricted stock units (&quot;PRSUs&quot;) 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 6, 2023 and the amount of PRSUs eligible for vesting was subject to certification of the satisfaction of certain performance conditions for the 2023 fiscal year by the Compensation Committee of the Board of Directors. On March 22, 2024, the Compensation Committee of the Board of Directors certified the achievement of the performance conditions for the PRSUs, which vest on February 1, 2026, subject to the filing person's continued employment with Chewy, Inc. through the vesting date.</footnote>
        <footnote id="F4">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. With respect to 20,292 of the RSUs, 33.33% will vest on February 1, 2026 and 33.33% will vest on each six-month anniversary thereafter, subject to the filing person's continued employment with Chewy, Inc. through the applicable vesting date. With respect to 6,764 of the RSUs, 100% will vest on February 1, 2026, subject to the filing person's continued employment with Chewy, Inc. through the vesting date.</footnote>
        <footnote id="F5">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="F6">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. 8.41% will vest on November 1, 2025, 15.84% will vest on December 1, 2025, and 8.41% will vest on February 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="F7">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>

    <remarks>Exhibit 24: Power of Attorney</remarks>

    <ownerSignature>
        <signatureName>/s/ Da-Wai Hu, as Attorney-in-Fact for Satish Mehta</signatureName>
        <signatureDate>2025-08-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
