NEW YORK, NY – June 21, 2021 – Integral Ad Science (“IAS”), a global leader in digital ad verification, today announced the launch of its initial public offering of 15,000,000 shares of its common stock pursuant to a registration statement on Form S-1 filed with the U.S. Securities and Exchange Commission (“SEC”). The initial public offering price is currently expected to be between $15 and $17 per share. The underwriters will have a 30-day option to purchase up to an additional 2,250,000 shares of common stock from IAS. IAS has been approved to list its common stock on the Nasdaq Stock Market under the ticker symbol “IAS.”

Morgan Stanley, Jefferies LLC, Barclays Capital Inc., and Evercore Group L.L.C., are acting as lead book-running managers for the offering. Wells Fargo Securities, LLC, BMO Capital Markets Corp., Oppenheimer & Co. Inc., Raymond James & Associates, Inc., and Stifel, Nicolaus & Company, Incorporated are acting as joint book-running managers for the offering. Academy Securities, Inc., Blaylock Van, LLC, Penserra Securities LLC, R. Seelaus & Co., LLC, and Siebert Williams Shank & Co., LLC are acting as co-managers for the offering.

The offering will be made only by means of a prospectus. Copies of the preliminary prospectus relating to this offering may be obtained from: Morgan Stanley & Co. LLC, 180 Varick Street, 2nd Floor, New York, NY 10014, Attention: Prospectus Department; Jefferies LLC, Attention: Equity Syndicate Prospectus Department, 520 Madison Avenue, 2nd Floor, New York, NY 10022, by telephone at (877) 821-7388, or by e-mail at prospectus_department@jefferies.com; Barclays Capital Inc., c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717, by telephone at 1-888-603-5847, or by email at barclaysprospectus@broadridge.com; and Evercore Group LLC, Attention: Equity Capital Markets, 55 East 52nd Street, New York, NY 10055, by telephone at (888) 474-0200, or by email at ecm.prospectus@evercore.com.

A registration statement relating to these securities has been filed with the SEC but has not yet become effective. These securities may not be sold, nor may offers to buy be accepted, prior to the time the registration statement becomes effective. This press release does not constitute an offer to sell or the solicitation of an offer to buy securities, and shall not constitute an offer, solicitation, or sale in any jurisdiction in which such offer, solicitation, or sale would be unlawful prior to registration or qualification under the securities laws of that jurisdiction.

About Integral Ad Science

Integral Ad Science (IAS) is a global leader in digital ad verification, ensuring that ads are viewable by real people in safe and suitable environments. IAS’s mission is to be the global benchmark for trust and transparency in digital media quality for the world’s leading brands, publishers, and platforms. We do this through data-driven technologies with actionable real-time signals and insight. Founded in 2009 and headquartered in New York, IAS works with thousands of top advertisers and premium publishers worldwide. IAS is part of the Vista Equity Partners portfolio of companies.

Forward-Looking Statements

This press release includes “forward-looking statements,” including with respect to the proposed initial public offering. Forward-looking statements are subject to known and unknown risks and uncertainties, many of which may be beyond our control. We caution you that the forward-looking information presented in this press release is not a guarantee of future events, and that actual events may differ materially from those made in or suggested by the forward-looking information contained in this press release. In addition, forward-looking statements generally can be identified by the use of forward-looking terminology such as “may,” “plan,” “seek,” “will,” “expect,” “intend,” “estimate,” “anticipate,” “believe” or “continue” or the negative thereof or variations thereon or similar terminology. Any forward-looking information presented herein is made only as of the date of this press release, and we do not undertake any obligation to update or revise any forward-looking information to reflect changes in assumptions, the occurrence of unanticipated events, or otherwise.

Media Contact

Julie Nicholson

Head of Communications

jnicholson@integralads.com

Investor Relations

Lally Zirkle

Investor Relations

Jonathan Schaffer

The Blueshirt Group, for IAS

ir@integralads.com