<SEC-DOCUMENT>0001127602-25-011699.txt : 20250404
<SEC-HEADER>0001127602-25-011699.hdr.sgml : 20250404
<ACCEPTANCE-DATETIME>20250404161529
ACCESSION NUMBER:		0001127602-25-011699
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20250402
FILED AS OF DATE:		20250404
DATE AS OF CHANGE:		20250404

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Morgan-Prager Karole
		CENTRAL INDEX KEY:			0001183627
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37924
		FILM NUMBER:		25814945

	MAIL ADDRESS:	
		STREET 1:		C/O BLACKLINE, INC.
		STREET 2:		21300 VICTORY BLVD., 12TH FLOOR
		CITY:			WOODLAND HILLS
		STATE:			CA
		ZIP:			91367

	FORMER NAME:	
		FORMER CONFORMED NAME:	PRAGER MORGAN KAROLE
		DATE OF NAME CHANGE:	20020828

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BLACKLINE, INC.
		CENTRAL INDEX KEY:			0001666134
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-PREPACKAGED SOFTWARE [7372]
		ORGANIZATION NAME:           	06 Technology
		EIN:				463354276
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		21300 VICTORY BOULEVARD
		STREET 2:		12TH FLOOR
		CITY:			WOODLAND HILLS
		STATE:			CA
		ZIP:			91367
		BUSINESS PHONE:		818-223-9008

	MAIL ADDRESS:	
		STREET 1:		21300 VICTORY BOULEVARD
		STREET 2:		12TH FLOOR
		CITY:			WOODLAND HILLS
		STATE:			CA
		ZIP:			91367
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>form4.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-04-02</periodOfReport>

    <issuer>
        <issuerCik>0001666134</issuerCik>
        <issuerName>BLACKLINE, INC.</issuerName>
        <issuerTradingSymbol>BL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001183627</rptOwnerCik>
            <rptOwnerName>Morgan-Prager Karole</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>21300 VICTORY BLVD., 12TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>WOODLAND HILLS</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>91367</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>1</isOfficer>
            <officerTitle>CHIEF LEGAL AND ADMINISTRATIVE</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-04-02</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>31520</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>129486</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Each share is represented by a Restricted Stock Unit (&quot;RSU&quot;). 25% of the RSUs will vest on the one (1) year anniversary of February 20, 2025 (the &quot;RSU Vesting Commencement Date&quot;), and 1/16th of the RSUs will vest every three months thereafter on the same day of the month as the RSU Vesting Commencement Date, subject to the reporting person's continued service through each applicable vesting date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Karole Morgan-Prager</signatureName>
        <signatureDate>2025-04-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
