<SEC-DOCUMENT>0001643523-16-000007.txt : 20160524
<SEC-HEADER>0001643523-16-000007.hdr.sgml : 20160524
<ACCEPTANCE-DATETIME>20160524200118
ACCESSION NUMBER:		0001643523-16-000007
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20160520
FILED AS OF DATE:		20160524
DATE AS OF CHANGE:		20160524

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			APPFOLIO INC
		CENTRAL INDEX KEY:			0001433195
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-PREPACKAGED SOFTWARE [7372]
		IRS NUMBER:				260359894
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		50 CASTILIAN DRIVE
		CITY:			GOLETA
		STATE:			CA
		ZIP:			93117
		BUSINESS PHONE:		8053646093

	MAIL ADDRESS:	
		STREET 1:		50 CASTILIAN DRIVE
		CITY:			GOLETA
		STATE:			CA
		ZIP:			93117

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Walker Jonathan
		CENTRAL INDEX KEY:			0001643523

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37468
		FILM NUMBER:		161673218

	MAIL ADDRESS:	
		STREET 1:		50 CASTILIAN DRIVE
		CITY:			GOLETA
		STATE:			CA
		ZIP:			93117
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_146413446305282.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2016-05-20</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001433195</issuerCik>
        <issuerName>APPFOLIO INC</issuerName>
        <issuerTradingSymbol>APPF</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001643523</rptOwnerCik>
            <rptOwnerName>Walker Jonathan</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>50 CASTILIAN DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SANTA BARBARA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>93117</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Technology Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Stock Option (Right to Buy)</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>13.43</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2016-05-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>50001</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2026-05-19</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>50001.0</value>
                    <footnoteId id="F3"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>50001</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The options were granted pursuant to the Issuer's 2015 Stock Incentive Plan.</footnote>
        <footnote id="F2">The options vest as to 50% of the underlying shares based upon the Issuer's achievement relative to pre-established targets relating to free cash flow for each of fiscal year 2017 and fiscal year 2018. The Issuer's performance relative to the targeted amount will be determined by the Compensation Committee by reference to the Issuer's 2017 and 2018 financial statements.</footnote>
        <footnote id="F3">The reported amount of shares assumes achievement at the maximum level, which would require performance at 150% of the targeted amount. For performance at the targeted amount, approximately 67% of the options would vest. For fiscal year 2017, Issuer performance below 50% of target will result in no options vesting.  For fiscal year 2018, Issuer performance below 80% of target will result in no options vesting.  The specific vesting percentages for Issuer achievement relative to the performance targets will be determined by reference to sliding vesting scales for each of fiscal year 2017 and 2018.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Ida Kane, as Attorney-In-Fact for Jonathan Walker</signatureName>
        <signatureDate>2016-05-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
