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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2014-01-29</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0001412270</issuerCik>
        <issuerName>Care.com Inc</issuerName>
        <issuerTradingSymbol>CRCM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001493921</rptOwnerCik>
            <rptOwnerName>Institutional Venture Management XIII, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>INSTITUTIONAL VENTURE PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>3000 SAND HILL RD, BLDG TWO, SUITE 250</rptOwnerStreet2>
            <rptOwnerCity>MENLO PARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001493922</rptOwnerCik>
            <rptOwnerName>Institutional Venture Partners XIII, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>INSTITUTIONAL VENTURE PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>3000 SAND HILL RD, BLDG TWO, SUITE 250</rptOwnerStreet2>
            <rptOwnerCity>MENLO PARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001300134</rptOwnerCik>
            <rptOwnerName>Chaffee Todd C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>INSTITUTIONAL VENTURE PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>3000 SAND HILL RD, BLDG TWO, SUITE 250</rptOwnerStreet2>
            <rptOwnerCity>MENLO PARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001140932</rptOwnerCik>
            <rptOwnerName>FOGELSONG NORMAN A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>INSTITUTIONAL VENTURE PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>3000 SAND HILL RD, BLDG TWO, SUITE 250</rptOwnerStreet2>
            <rptOwnerCity>MENLO PARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001299975</rptOwnerCik>
            <rptOwnerName>Harrick Stephen J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>INSTITUTIONAL VENTURE PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>3000 SAND HILL RD, BLDG TWO, SUITE 250</rptOwnerStreet2>
            <rptOwnerCity>MENLO PARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001359524</rptOwnerCik>
            <rptOwnerName>Miller J Sanford</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>INSTITUTIONAL VENTURE PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>3000 SAND HILL RD, BLDG TWO, SUITE 250</rptOwnerStreet2>
            <rptOwnerCity>MENLO PARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001299965</rptOwnerCik>
            <rptOwnerName>Phelps Dennis B</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>INSTITUTIONAL VENTURE PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>3000 SAND HILL RD, BLDG TWO, SUITE 250</rptOwnerStreet2>
            <rptOwnerCity>MENLO PARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, $0.001 par value</value>
            </securityTitle>
            <transactionDate>
                <value>2014-01-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2375530</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2492080</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Fotnote</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Series E Convertible Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2014-01-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2375530</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F4"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2375530</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Fotnote</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each share of Series E Convertible Preferred Stock automatically convered into one share of Issuer's Common stock upon the consummation of Issuer's initial public offering.</footnote>
        <footnote id="F2">The shares are held of record by Institutional Venture Partners XIII, L.P.  (&quot;IVP XIII&quot;).  Institutional Venture Management XIII LLC (&quot;IVM XIII&quot;) is the general partner of IVP XIII.  Todd C Chaffee, Norman A. Fogelsong, Stephen J. Harrick, J. Sanford Miller and Dennis B. Phelps, as the managing directors of IVM XIII, may be deemed to have shared voting and dispositive power with respect to the shares held by IVP XIII.  Each of these reporting individuals disclaims beneficial ownership of the securities reported herein, except to the extent of his respective pecuniary interest therein.</footnote>
        <footnote id="F3">The Series E Convertible Preferred Stock automatically converts into shares of Issuer's Common Stock on a 1:1 basis upon the completion of Issuer's initial public offering.</footnote>
        <footnote id="F4">The expiration date is not relevant to the conversion of these securities.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>INSTITUTIONAL VENTURE PARTNERS XIII, L.P. By: Institutional Venture Management XIII LLC its General Partner By: /s/ Melanie Chladek Chief Financial Officer</signatureName>
        <signatureDate>2014-01-29</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Institutional Venture Management XIII, LLC By: /s/ Melanie Chladek, Chief Financial Officer</signatureName>
        <signatureDate>2014-01-29</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Melanie Chladek as Attorney-in-Fact for Todd C. Chaffee</signatureName>
        <signatureDate>2014-01-29</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Melanie Chladek as Attorney-in-Fact for Norman A. Fogelsong</signatureName>
        <signatureDate>2014-01-29</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Melanie Chladek as Attorney-in-Fact for Stephen J. Harrick</signatureName>
        <signatureDate>2014-01-29</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Melanie Chladek as Attorney-in-Fact for J. Sanford Miller</signatureName>
        <signatureDate>2014-01-29</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Melanie Chladek as Attorney-in-Fact for Dennis B. Phelps</signatureName>
        <signatureDate>2014-01-29</signatureDate>
    </ownerSignature>
</ownershipDocument>
