<SEC-DOCUMENT>0001209191-19-036006.txt : 20190610
<SEC-HEADER>0001209191-19-036006.hdr.sgml : 20190610
<ACCEPTANCE-DATETIME>20190610203825
ACCESSION NUMBER:		0001209191-19-036006
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20190607
FILED AS OF DATE:		20190610
DATE AS OF CHANGE:		20190610

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Hank Jeffrey P
		CENTRAL INDEX KEY:			0001329632

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35662
		FILM NUMBER:		19889757

	MAIL ADDRESS:	
		STREET 1:		C/O INTUIT INC.
		STREET 2:		PO BOX 7850
		CITY:			MOUNTAIN VIEW
		STATE:			CA
		ZIP:			94039

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			QUALYS, INC.
		CENTRAL INDEX KEY:			0001107843
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-PREPACKAGED SOFTWARE [7372]
		IRS NUMBER:				770534145
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		919 E. HILLSDALE BLVD.
		CITY:			FOSTER CITY
		STATE:			CA
		ZIP:			94404
		BUSINESS PHONE:		650-801-6100

	MAIL ADDRESS:	
		STREET 1:		919 E. HILLSDALE BLVD.
		CITY:			FOSTER CITY
		STATE:			CA
		ZIP:			94404

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	QUALYS INC
		DATE OF NAME CHANGE:	20000225
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-06-07</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001107843</issuerCik>
        <issuerName>QUALYS, INC.</issuerName>
        <issuerTradingSymbol>QLYS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001329632</rptOwnerCik>
            <rptOwnerName>Hank Jeffrey P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O QUALYS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>919 E. HILLSDALE BLVD.</rptOwnerStreet2>
            <rptOwnerCity>FOSTER CITY</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94404</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2019-06-07</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2271</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>11014</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The reported securities represent restricted stock units which vest on the earlier of (i) June 7, 2020 or (ii) the day before the Issuer's 2020 annual meeting of stockholders, subject to the Reporting Person's continued service through each such vesting date.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Bruce Posey by power of attorney</signatureName>
        <signatureDate>2019-06-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
