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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-02-15</periodOfReport>

    <issuer>
        <issuerCik>0000050863</issuerCik>
        <issuerName>INTEL CORP</issuerName>
        <issuerTradingSymbol>INTC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001316331</rptOwnerCik>
            <rptOwnerName>GELSINGER PATRICK P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O INTEL CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>2200 MISSION COLLEGE BLVD</rptOwnerStreet2>
            <rptOwnerCity>SANTA CLARA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95054</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <officerTitle>CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

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                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
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            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
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                    <value>421620</value>
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                <transactionPricePerShare>
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            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
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                </underlyingSecurityShares>
            </underlyingSecurity>
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                </sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
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        <derivativeTransaction>
            <securityTitle>
                <value>Performance-Based Stock Units (PSUs)</value>
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                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
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                </transactionShares>
                <transactionPricePerShare>
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            <expirationDate>
                <footnoteId id="F4"/>
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                <underlyingSecurityTitle>
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                <directOrIndirectOwnership>
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            <securityTitle>
                <value>Performance-Based Stock Units (PSUs)</value>
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            <transactionTimeliness></transactionTimeliness>
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                <transactionPricePerShare>
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                </transactionAcquiredDisposedCode>
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            <expirationDate>
                <footnoteId id="F6"/>
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                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
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                    <value>457789</value>
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            </underlyingSecurity>
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                <sharesOwnedFollowingTransaction>
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                </sharesOwnedFollowingTransaction>
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                <directOrIndirectOwnership>
                    <value>D</value>
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        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Performance-Based Stock Units (PSUs)</value>
            </securityTitle>
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            </conversionOrExercisePrice>
            <transactionDate>
                <value>2021-02-15</value>
            </transactionDate>
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                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>3275199</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F7"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
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            <expirationDate>
                <footnoteId id="F6"/>
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                <underlyingSecurityTitle>
                    <value>Common Stock</value>
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            </underlyingSecurity>
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                    <value>3275199</value>
                </sharesOwnedFollowingTransaction>
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                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>61.81</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2021-02-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2083638</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F8"/>
            </exerciseDate>
            <expirationDate>
                <value>2031-02-15</value>
                <footnoteId id="F8"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2083638</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2083638</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each restricted stock unit (RSU) represents the right to receive, following vesting, one share of Intel Corporation common stock.</footnote>
        <footnote id="F2">Unless earlier forfeited under the terms of the RSU, 1/12th of the awards vest and convert into common stock in twelve substantially equal quarterly tranches, beginning on May 15, 2021. If the quarterly vesting date falls on a non-business date, the next business date shall apply.</footnote>
        <footnote id="F3">Each performance-based stock unit (PSU) represents the contingent right to receive, subject to vesting, up to 200% of one share of Intel Corporation (Intel) common stock on March 15, 2024, or the next business date, if applicable.</footnote>
        <footnote id="F4">Unless earlier forfeited under the terms of the PSUs, the number of shares of Intel common stock acquired upon vesting of the PSUs is contingent upon the achievement of Intel's total shareholder return (TSR) relative to the TSR of the S&amp;P 500 IT Index over a three-year period commencing with the grant date, as further described in the Offer Letter between Intel and the reporting person dated January 13, 2021 (Offer Letter), Exhibit 10.1 to Intel's Current Report on Form 8-K filed with the Securities and Exchange Commission on January 14, 2021.</footnote>
        <footnote id="F5">Each PSU represents the contingent right to receive, subject to vesting, up to 200% of one share of Intel common stock based on the appreciation in Intel's closing stock price over the five-year period following the grant date.</footnote>
        <footnote id="F6">Unless earlier forfeited under the terms of the PSUs, on the third anniversary of the grant date (or the next business date if applicable), these PSUs may vest in respect of up to half of the shares of Intel common stock subject to the PSUs, and on the fifth anniversary of the grant date (or the next business date if applicable), these PSUs may vest in respect of all of the shares of Intel common stock subject to the PSUs not previously vested. The number of shares of Intel common stock acquired upon any vesting of the PSUs is contingent upon the achievement of certain pre-established performance metrics, approved by the Compensation Committee of the Intel Board of Directors (Compensation Committee), during the three- and five-year performance periods following the grant date, as further described in the Offer Letter.</footnote>
        <footnote id="F7">Each PSU represents the contingent right to receive, subject to vesting, one share of Intel common stock based on the appreciation in Intel's closing stock price over the five-year period following the grant date.</footnote>
        <footnote id="F8">Unless earlier forfeited under the terms of the option, the option vests in equal annual installments on the first four anniversaries of the grant date. The option shall become exercisable only if, during the five-year performance period following the grant date, a certain pre-established performance metric, approved by the Compensation Committee, is achieved, as further described in the Offer Letter.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Alex Shukhman, attorney-in-fact</signatureName>
        <signatureDate>2021-02-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
