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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2014-02-14</periodOfReport>

    <issuer>
        <issuerCik>0001468516</issuerCik>
        <issuerName>AOL Inc.</issuerName>
        <issuerTradingSymbol>AOL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001584517</rptOwnerCik>
            <rptOwnerName>Rosenthal Donald</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>22000 AOL WAY</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>DULLES</rptOwnerCity>
            <rptOwnerState>VA</rptOwnerState>
            <rptOwnerZipCode>20166</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>1</isOfficer>
            <officerTitle>SVP &amp; CEO AOL Membership Group</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, Par Value $0.01</value>
            </securityTitle>
            <transactionDate>
                <value>2014-02-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4481</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>35211</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, Par Value $0.01</value>
            </securityTitle>
            <transactionDate>
                <value>2014-02-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1058</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>44.63</value>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>34153</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>44.63</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2014-02-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>12626</value>
                    <footnoteId id="F4"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F5"/>
            </exerciseDate>
            <expirationDate>
                <value>2024-02-13</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock, Par Value $0.01</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>12626</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>12626</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Performance Rights</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F6"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2014-02-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4481</value>
                    <footnoteId id="F6"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F7"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F7"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock, Par Value $0.01</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>4481</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4481</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Represents restricted stock units granted pursuant to the AOL Inc. 2010 Stock Incentive Plan, as amended and restated (the &quot;Plan&quot;). This award of restricted stock units will vest over three years such that one third of the restricted stock units will vest on February 14, 2015, and the remaining two thirds will vest in two equal installments on February 14, 2016 and February 14, 2017. This award of restricted stock units will be paid in stock to the Reporting Person within sixty days of vesting.</footnote>
        <footnote id="F2">On February 15, 2014, 3,192 restricted stock units previously granted to the Reporting Person vested. In this regard, the Reporting Person received 2,134 shares of AOL Inc. (the &quot;Company&quot;) common stock (&quot;shares&quot;) and 1,058 shares were withheld automatically in accordance with the Reporting Person's Restricted Stock Units Agreement with the Company in order to satisfy the tax liability that arose upon vesting of the restricted stock units.</footnote>
        <footnote id="F3">Reflects the closing price of the shares on February 14, 2014.</footnote>
        <footnote id="F4">Represents stock options granted pursuant to the Plan.</footnote>
        <footnote id="F5">The shares subject to the stock option vest and become exercisable over a three-year period. Subject to the Reporting Person's continuous employment on each vesting date, one third of the shares subject to the option will vest and become exercisable on February 14, 2015 and the remaining shares subject to the stock option will vest and become exercisable on a pro rata monthly basis for the 24 month period thereafter.</footnote>
        <footnote id="F6">Represents performance rights granted pursuant to the Plan.</footnote>
        <footnote id="F7">Each performance right represents a contingent right to receive one share of AOL Inc. (the &quot;Company&quot;) common stock. The vesting of the performance rights is based on the relative Total Shareholder Return (&quot;TSR&quot;) of the Company as compared to the TSR of each of the companies in the Company's peer group over the period beginning January 1, 2014 and ending December 31, 2016 and subject to the Reporting Person's continuous employment through the vesting date. Performance rights granted represents the target shares and actual performance rights earned could be anywhere from 0 to 200% of the number of performance rights granted. The performance rights expire upon payout, if any, of the award.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Uche Ndumele as authorized signatory for Donald Rosenthal</signatureName>
        <signatureDate>2014-02-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
