<SEC-DOCUMENT>0001140361-15-011010.txt : 20150309
<SEC-HEADER>0001140361-15-011010.hdr.sgml : 20150309
<ACCEPTANCE-DATETIME>20150309192052
ACCESSION NUMBER:		0001140361-15-011010
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20150305
FILED AS OF DATE:		20150309
DATE AS OF CHANGE:		20150309

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CODEXIS INC
		CENTRAL INDEX KEY:			0001200375
		STANDARD INDUSTRIAL CLASSIFICATION:	INDUSTRIAL ORGANIC CHEMICALS [2860]
		IRS NUMBER:				710872999
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		200 PENOBSCOT DRIVE
		CITY:			REDWOOD CITY
		STATE:			CA
		ZIP:			94063
		BUSINESS PHONE:		650-421-8100

	MAIL ADDRESS:	
		STREET 1:		200 PENOBSCOT DRIVE
		CITY:			REDWOOD CITY
		STATE:			CA
		ZIP:			94063

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			NICOLS JOHN J
		CENTRAL INDEX KEY:			0001238884

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34705
		FILM NUMBER:		15686704

	MAIL ADDRESS:	
		STREET 1:		ALBEMARLE CORP
		STREET 2:		451 FLORIDA ST
		CITY:			BATON ROUGE
		STATE:			LA
		ZIP:			70801
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2015-03-05</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001200375</issuerCik>
        <issuerName>CODEXIS INC</issuerName>
        <issuerTradingSymbol>CDXS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001238884</rptOwnerCik>
            <rptOwnerName>NICOLS JOHN J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O CODEXIS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>200 PENOBSCOT DRIVE</rptOwnerStreet2>
            <rptOwnerCity>REDWOOD CITY</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94063</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and CEO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2015-03-05</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>40789</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.99</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>932499</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Shares withheld by the Issuer on vesting of performance stock units solely to cover applicable withholding taxes. No shares were sold in the open market; the transaction reported herein was executed automatically upon the release of shares of stock acquired by the Reporting Person pursuant to the prior achievement of performance metrics as determined by the Issuer's compensation committee.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Doug Sheehy, Attorney-in-Fact for John Nicols</signatureName>
        <signatureDate>2015-03-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
