<SEC-DOCUMENT>0001433195-17-000049.txt : 20170811
<SEC-HEADER>0001433195-17-000049.hdr.sgml : 20170811
<ACCEPTANCE-DATETIME>20170811182646
ACCESSION NUMBER:		0001433195-17-000049
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20170808
FILED AS OF DATE:		20170811
DATE AS OF CHANGE:		20170811

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Donahoo Brian
		CENTRAL INDEX KEY:			0001643443

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37468
		FILM NUMBER:		171026419

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

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
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_150249039206025.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-08-08</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001643443</rptOwnerCik>
            <rptOwnerName>Donahoo Brian</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>50 CASTILIAN DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>GOLETA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>93117</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle></officerTitle>
            <otherText>Former Director,Pres &amp; CEO (3)</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class B Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>996149</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By trust</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Each share of Class B Common Stock is convertible, at any time at the option of the holder, into one share of Class A Common Stock. In addition, each share of Class B Common Stock will convert automatically into one share of Class A Common Stock upon any transfer, except for any transfers by (i) a partnership or limited liability company that was a registered holder of shares of Class B Common Stock to anyone who was a partner or member of any such partnership or limited liability company at the effective time, and (ii) a transfer to a &quot;qualified recipient,&quot; as defined in the Issuer's amended and restated certificate of incorporation. The shares of Class B Common Stock have no expiration date.</footnote>
        <footnote id="F2">All of the outstanding shares of Class B Common Stock will convert automatically into shares of Class A Common Stock, on a one share-for-one share basis, on the date when the number of the Company's outstanding shares of Class B Common Stock represents less than 10% of the sum of its outstanding shares of Class A Common Stock and Class B Common Stock.</footnote>
        <footnote id="F3">On August 8, 2017, Brian Donahoo retired from his position on the Issuer's Board of Directors and as its President and Chief Executive Officer. Mr. Donahoo is filing this Form 4 for the sole purpose of confirming that he is no longer subject to Section 16 as an officer or director of the Issuer.</footnote>
        <footnote id="F4">The shares of Class B Common Stock reported on the table above are held by the Brian R Donahoo 2015 Revocable Trust of which Mr. Donahoo is the trustee.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Ida Kane, as Attorney-in-Fact for Brian Donahoo</signatureName>
        <signatureDate>2017-08-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
