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

    <schemaVersion>X0304</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2012-03-01</periodOfReport>

    <issuer>
        <issuerCik>0001288776</issuerCik>
        <issuerName>Google Inc.</issuerName>
        <issuerTradingSymbol>GOOG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001468233</rptOwnerCik>
            <rptOwnerName>Arora Nikesh</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O GOOGLE INC.</rptOwnerStreet1>
            <rptOwnerStreet2>1600 AMPHITHEATRE PARKWAY</rptOwnerStreet2>
            <rptOwnerCity>MOUNTAIN VIEW</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94043</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>1</isOfficer>
            <officerTitle>SVP and Chief Business Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Google Stock Unit</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2012-03-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>684</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>14313</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2012-03-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>684</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1510</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Google Stock Unit</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2012-03-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>566</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>618.25</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>13747</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Google Stock Unit</value>
                <footnoteId id="F3"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2812</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Google Stock Unit</value>
                <footnoteId id="F4"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>8471</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Google Stock Unit</value>
                <footnoteId id="F5"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>18713</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Google Stock Unit</value>
                <footnoteId id="F6"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5335</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Option To Purchase Class A Common Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>564.35</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F7"/>
            </exerciseDate>
            <expirationDate>
                <value>2020-12-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>39990</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>39990</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Option To Purchase Class A Common Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>574.18</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F8"/>
            </exerciseDate>
            <expirationDate>
                <value>2021-04-06</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>39050</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>39050</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Option To Purchase Class A Common Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>308.57</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F9"/>
            </exerciseDate>
            <expirationDate>
                <value>2017-10-05</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1667</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1667</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Option To Purchase Class A Common Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>308.57</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F10"/>
            </exerciseDate>
            <expirationDate>
                <value>2017-10-05</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1167</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1167</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Option To Purchase Class A Common Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>318.92</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F11"/>
            </exerciseDate>
            <expirationDate>
                <value>2019-03-04</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>9246</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>9246</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The Google Stock Units (&quot;GSUs&quot;) entitle the reporting person to receive one share of Google Inc.'s Class A Common Stock for each share underlying the GSU as the GSU vests. The GSUs vest as follows: 1/4th of the GSUs shall vest on the one-year grant date anniversary and 1/16th each quarter thereafter until the units are fully vested, subject to continued employment with Google on the applicable vesting dates.</footnote>
        <footnote id="F2">Shares withheld to satisfy tax obligations upon vesting of GSUs.</footnote>
        <footnote id="F3">The Google Stock Units (&quot;GSUs&quot;) entitle the reporting person to receive one share of Google Inc.'s Class A Common Stock for each share underlying the GSU as the GSU vests. The GSUs vest as follows: 2,812 of the GSUs shall vest on 9/5/09, 2,811 of the GSUs shall vest on 12/5/09, 2,812 of the GSUs shall vest on 3/5/10, 2,812 of the GSUs shall vest on 6/5/10, 2,811 of the GSUs shall vest on 9/5/10, 2,812 of the GSUs shall vest on 12/5/10, 2,811 of the GSUs shall vest on 3/5/11, 2,812 of the GSUs shall vest on 6/5/11, 2,811 of the GSUs shall vest on 9/5/11, 2,812 of the GSUs shall vest on 12/5/11 and 2,812 of the GSUs shall vest on 3/5/12, subject to continued employment with Google on the applicable vesting dates.</footnote>
        <footnote id="F4">The Google Stock Units (&quot;GSUs&quot;) entitle the reporting person to receive one share of Google Inc.'s Class A Common Stock for each share underlying the GSU as the GSU vests. The GSUs vest as follows: 6,776 of the GSUs shall vest on 4/15/10 and 1/16th of the GSUs shall vest each quarter thereafter until the units are fully vested, subject to continued employment with Google on the applicable vesting dates.</footnote>
        <footnote id="F5">The Google Stock Units (&quot;GSUs&quot;) entitle the reporting person to receive one share of Google Inc.'s Class A Common Stock for each share underlying the GSU as the GSU vests. The GSUs vest as follows: 1/48th of the GSUs shall vest on the vesting start date (1/6/2012) and 1/48th each month thereafter until the units are fully vested, subject to continued employment with Google on the applicable vesting dates.</footnote>
        <footnote id="F6">The Google Stock Units (&quot;GSUs&quot;) entitle the reporting person to receive one share of Google Inc.'s Class A Common Stock for each share underlying the GSU as the GSU vests. The GSUs vest as follows: 4,267 of the GSUs shall vest on 3/4/10 and 1/16th of the GSUs shall vest each quarter thereafter until the units are fully vested, subject to continued employment with Google on the applicable vesting dates.</footnote>
        <footnote id="F7">The option provided for vesting as follows: 1/4th of the option shall vest on the one-year grant date anniversary and 1/48th each month thereafter until the option is fully vested, subject to continued employment with Google on the applicable vesting dates.</footnote>
        <footnote id="F8">The option provided for vesting as follows: 1/48th of the option shall vest on the vesting start date (1/6/12) and 1/48th each month thereafter until the option is fully vested, subject to continued employment with Google on the applicable vesting dates.</footnote>
        <footnote id="F9">The option provides for vesting as follows: 2,500 shares shall vest on 10/5/09 and 1/48th of the total option shall vest each month thereafter until the option is fully vested, subject to continued employment with Google on the applicable vesting dates.</footnote>
        <footnote id="F10">The option provides for vesting as follows: 1,750 shares shall vest on 10/5/09 and 1/48th of the total option shall vest each month thereafter until the option is fully vested, subject to continued employment with Google on the applicable vesting dates.</footnote>
        <footnote id="F11">The option provides for vesting as follows: 8,534 shares shall vest on 3/4/10 and 1/48th of the total option shall vest each month thereafter until the option is fully vested, subject to continued employment with Google on the applicable vesting dates.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Valentina Margulis, as attorney-in-fact for Nikesh Arora</signatureName>
        <signatureDate>2012-03-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
