<SEC-DOCUMENT>0001628280-25-000690.txt : 20250106
<SEC-HEADER>0001628280-25-000690.hdr.sgml : 20250106
<ACCEPTANCE-DATETIME>20250106193516
ACCESSION NUMBER:		0001628280-25-000690
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20250102
FILED AS OF DATE:		20250106
DATE AS OF CHANGE:		20250106

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Margolis Joseph D
		CENTRAL INDEX KEY:			0001330121
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-32269
		FILM NUMBER:		25513082

	MAIL ADDRESS:	
		STREET 1:		C/O ARSENAL REAL ESTATE FUNDS
		STREET 2:		117 ON THE GREEN, 67 PARK PLACE EAST
		CITY:			MORRISTOWN
		STATE:			NJ
		ZIP:			07960

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Extra Space Storage Inc.
		CENTRAL INDEX KEY:			0001289490
		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE INVESTMENT TRUSTS [6798]
		ORGANIZATION NAME:           	05 Real Estate & Construction
		IRS NUMBER:				201076777
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2795 COTTONWOOD PARKWAY, SUITE 400
		CITY:			SALT LAKE CITY
		STATE:			UT
		ZIP:			84121
		BUSINESS PHONE:		801-562-5556

	MAIL ADDRESS:	
		STREET 1:		2795 COTTONWOOD PARKWAY, SUITE 400
		CITY:			SALT LAKE CITY
		STATE:			UT
		ZIP:			84121
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wk-form4_1736210110.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-01-02</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001289490</issuerCik>
        <issuerName>Extra Space Storage Inc.</issuerName>
        <issuerTradingSymbol>EXR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001330121</rptOwnerCik>
            <rptOwnerName>Margolis Joseph D</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2795 EAST COTTONWOOD PARKWAY</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 300</rptOwnerStreet2>
            <rptOwnerCity>SALT LAKE CITY</rptOwnerCity>
            <rptOwnerState>UT</rptOwnerState>
            <rptOwnerZipCode>84121</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Executive Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-01-02</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>7500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>148.01</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>16690</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Cove Hollow Lane II, LLC</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>61865</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>34760</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>J Margolis &amp; K Margolis TTEE</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>97260</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Cove Hollow Lane I, LLC</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person dated as of March 1, 2024.</footnote>
        <footnote id="F2">The reporting person disclaims beneficial ownership in the common stock held by Cove Hollow Lane II, LLC, except to the extent of his pecuniary interest therein.</footnote>
        <footnote id="F3">Shares held in J Margolis &amp; K Margolis TTEE Joseph Daniel Margolis Revocab U/A DTD 05/24/2013.</footnote>
        <footnote id="F4">The reporting person controls the investment decisions with respect to shares of common stock held by Cove Hollow Lane I, LLC.  The reporting person disclaims beneficial ownership in the common stock held by Cove Hollow Lane I, LLC, except to the extent of his pecuniary interest therein.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Grace Kunde, Attorney-in-Fact</signatureName>
        <signatureDate>2025-01-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
