<SEC-DOCUMENT>0001562180-24-007894.txt : 20241122
<SEC-HEADER>0001562180-24-007894.hdr.sgml : 20241122
<ACCEPTANCE-DATETIME>20241122194029
ACCESSION NUMBER:		0001562180-24-007894
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20241120
FILED AS OF DATE:		20241122
DATE AS OF CHANGE:		20241122

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Vattuone Steven
		CENTRAL INDEX KEY:			0001335061
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-39965
		FILM NUMBER:		241491588

	MAIL ADDRESS:	
		STREET 1:		139 TOWNSEND ST
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94107

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ON24 INC.
		CENTRAL INDEX KEY:			0001110611
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-PREPACKAGED SOFTWARE [7372]
		ORGANIZATION NAME:           	06 Technology
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		50 BEALE STREET, 8TH FLOOR
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94105
		BUSINESS PHONE:		(415) 369-8000

	MAIL ADDRESS:	
		STREET 1:		50 BEALE STREET, 8TH FLOOR
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94105

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ON24 INC
		DATE OF NAME CHANGE:	20000329
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primarydocument.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2024-11-20</periodOfReport>

    <notSubjectToSection16>false</notSubjectToSection16>

    <issuer>
        <issuerCik>0001110611</issuerCik>
        <issuerName>ON24 INC.</issuerName>
        <issuerTradingSymbol>ONTF</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001335061</rptOwnerCik>
            <rptOwnerName>Vattuone Steven</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ON24, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>50 BEALE STREET, 8TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94015</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>false</isDirector>
            <isOfficer>true</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle>Chief Financial Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>true</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2024-11-20</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>false</equitySwapInvolved>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4383.00</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.2861</value>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>583591.00</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The transaction reported in this Form 4 was effected pursuant to a Rule 10B5-1 trading plan adopted by the reporting person on September 14, 2023.</footnote>
        <footnote id="F2">Represents the number of shares sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of restricted stock units.</footnote>
        <footnote id="F3">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $6.24 to $ 6.36 inclusive. The reporting person undertakes to provide to Issuer, any security holder of Issuer, or the staff of the Security and Exchange Commission, upon request, full information regarding the number of shares sold in each separate price within the ranges set forth in footnote (3) to this Form 4.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Vattuone Steven by Charles Rogerson, as Attorney-in-Fact</signatureName>
        <signatureDate>2024-11-22</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
