<?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:com="http://www.sec.gov/edgar/common">
  <!-- Generated by Workiva -->
  <headerData>
    <submissionType>144</submissionType>
    <filerInfo>
      <filer>
        <filerCredentials>
          <cik>0002024441</cik>
          <ccc>XXXXXXXX</ccc>
        </filerCredentials>
      </filer>
      <liveTestFlag>LIVE</liveTestFlag>



    </filerInfo>
  </headerData>
  <formData>
    <issuerInfo>
      <issuerCik>0001517413</issuerCik>
      <issuerName>Fastly, Inc.</issuerName>
      <secFileNumber>001-38897</secFileNumber>
      <issuerAddress>
        <com:street1>475 Brannan Street</com:street1>
        <com:street2>Suite 300</com:street2>
        <com:city>San Francisco</com:city>
        <com:stateOrCountry>CA</com:stateOrCountry>
        <com:zipCode>94107</com:zipCode>
      </issuerAddress>
      <issuerContactPhone>8444357859</issuerContactPhone>
      <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Scott Lovett</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
      <relationshipsToIssuer>
        <relationshipToIssuer>Officer</relationshipToIssuer>
      </relationshipsToIssuer>
    </issuerInfo>
    <securitiesInformation>
      <securitiesClassTitle>COMMON</securitiesClassTitle>
      <brokerOrMarketmakerDetails>
        <name>E*TRADE SECURITIES LLC.</name>
        <address>
          <com:street1>4005 Windward Plaza Dr.</com:street1>
          <com:city>Alpharetta</com:city>
          <com:stateOrCountry>GA</com:stateOrCountry>
          <com:zipCode>30005</com:zipCode>
        </address>
      </brokerOrMarketmakerDetails>
      <noOfUnitsSold>33950</noOfUnitsSold>
      <aggregateMarketValue>377524</aggregateMarketValue>
      <noOfUnitsOutstanding>151276665</noOfUnitsOutstanding>
      <approxSaleDate>12/16/2025</approxSaleDate>
      <securitiesExchangeName>NYSE</securitiesExchangeName>
    </securitiesInformation>
    <securitiesToBeSold>
      <securitiesClassTitle>COMMON</securitiesClassTitle>
      <acquiredDate>12/15/2025</acquiredDate>
      <natureOfAcquisitionTransaction>RESTRICTED</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>FASTLY, INC.</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>33950</amountOfSecuritiesAcquired>
      <paymentDate>12/15/2025</paymentDate>
      <natureOfPayment>N/A</natureOfPayment>
    </securitiesToBeSold>
    <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
    <securitiesSoldInPast3Months>
      <sellerDetails>
        <name>Scott Lovett</name>
        <address>
          <com:street1>475 Brannan Street, Suite 300</com:street1>
          <com:city>San Francisco</com:city>
          <com:stateOrCountry>CA</com:stateOrCountry>
          <com:zipCode>94107</com:zipCode>
        </address>
      </sellerDetails>
      <securitiesClassTitle>Class A Common Stock</securitiesClassTitle>
      <saleDate>09/15/2025</saleDate>
      <amountOfSecuritiesSold>178931</amountOfSecuritiesSold>
      <grossProceeds>1481548.68</grossProceeds>
    </securitiesSoldInPast3Months>
    <securitiesSoldInPast3Months>
      <sellerDetails>
        <name>Scott Lovett</name>
        <address>
          <com:street1>475 Brannan Street, Suite 300</com:street1>
          <com:city>San Francisco</com:city>
          <com:stateOrCountry>CA</com:stateOrCountry>
          <com:zipCode>94107</com:zipCode>
        </address>
      </sellerDetails>
      <securitiesClassTitle>Class A Common Stock</securitiesClassTitle>
      <saleDate>09/16/2025</saleDate>
      <amountOfSecuritiesSold>34462</amountOfSecuritiesSold>
      <grossProceeds>297407.06</grossProceeds>
    </securitiesSoldInPast3Months>
    <securitiesSoldInPast3Months>
      <sellerDetails>
        <name>Scott Lovett</name>
        <address>
          <com:street1>475 Brannan Street, Suite 300</com:street1>
          <com:city>San Francisco</com:city>
          <com:stateOrCountry>CA</com:stateOrCountry>
          <com:zipCode>94107</com:zipCode>
        </address>
      </sellerDetails>
      <securitiesClassTitle>Class A Common Stock</securitiesClassTitle>
      <saleDate>09/17/2025</saleDate>
      <amountOfSecuritiesSold>42172</amountOfSecuritiesSold>
      <grossProceeds>354666.52</grossProceeds>
    </securitiesSoldInPast3Months>
    <securitiesSoldInPast3Months>
      <sellerDetails>
        <name>Scott Lovett</name>
        <address>
          <com:street1>475 Brannan Street, Suite 300</com:street1>
          <com:city>San Francisco</com:city>
          <com:stateOrCountry>CA</com:stateOrCountry>
          <com:zipCode>94107</com:zipCode>
        </address>
      </sellerDetails>
      <securitiesClassTitle>Class A Common Stock</securitiesClassTitle>
      <saleDate>11/18/2025</saleDate>
      <amountOfSecuritiesSold>9779</amountOfSecuritiesSold>
      <grossProceeds>100039.17</grossProceeds>
    </securitiesSoldInPast3Months>
    <noticeSignature>
      <noticeDate>12/12/2025</noticeDate>
      <signature>/s/ Tara Seracka, Attorney-in-Fact for Scott Lovett</signature>
    </noticeSignature>
  </formData>
</edgarSubmission>
