<SUBMISSION>
<ACCESSION-NUMBER>0001254115-04-000001
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20041122
<FILING-DATE>20041123
<DATE-OF-FILING-DATE-CHANGE>20041123
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>ANDREWS BARRY
<CIK>0001254115
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>000-21783
<FILM-NUMBER>041164034
</FILING-VALUES>
<MAIL-ADDRESS>
<STREET1>C/O 8X8 INC
<STREET2>2445 MISSION COLLEGE BLVD
<CITY>SANTA CLARA
<STATE>CA
<ZIP>95054
</MAIL-ADDRESS>
</REPORTING-OWNER>
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>8X8 INC /DE/
<CIK>0001023731
<ASSIGNED-SIC>4813
<IRS-NUMBER>770142404
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>0331
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>2445 MISSION COLLEGE BLVD
<CITY>SANTA CLARA
<STATE>CA
<ZIP>95054
<PHONE>4087271885
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>2445 MISSION COLLEGE BLVD
<CITY>SANTA CLARA
<STATE>CA
<ZIP>95054
</MAIL-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>NETERGY NETWORKS INC
<DATE-CHANGED>20000912
</FORMER-COMPANY>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>8X8 INC
<DATE-CHANGED>19961023
</FORMER-COMPANY>
</ISSUER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-11-22</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001023731</issuerCik>
        <issuerName>8X8 INC /DE/</issuerName>
        <issuerTradingSymbol>eght</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001254115</rptOwnerCik>
            <rptOwnerName>ANDREWS BARRY</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O 8X8 INC</rptOwnerStreet1>
            <rptOwnerStreet2>3151 JAY STREET</rptOwnerStreet2>
            <rptOwnerCity>SANTA CLARA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95054</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>3.35</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-11-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>100000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2014-11-22</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>100000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>648177</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The option becomes exercisable at the rate of 1/48th of the shares on 12/22/2004 and at the end of each full month thereafter.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Barry Andrews</signatureName>
        <signatureDate>2004-11-22</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
