Item 1.01. Entry into a Material Definitive Agreement. On May 26, 2026, Synopsys, Inc. (“ Synopsys”) entered into a Cooperation Agreement (the “ Agreement”) with Elliott Investment Management L. P., Elliott Associates, L. P. and Elliott International, L. P. (collectively, “ Elliott”). Pursuant to the Agreement, the Board of Directors of Synopsys (the “ Board”) agreed to increase the size of the Board by one, appoint Jesse Cohn to the Board, effective as of June 1, 2026 (the “ Effective Date”), with an initial term expiring at Synopsys’ 2027 annual meeting of stockholders (the “2027 Annual Meeting”). The Board also agreed to appoint Mr. Cohn to the Corporate Governance and Nominating Committee of the Board and include Mr. Cohn in Synopsys’ slate of nominees for election at the 2027 Annual Meeting.

Item 5.02. Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers. The description of the matters included under Item 1.01 are incorporated into this Item 5.02 by reference. There are no arrangements or understandings between Mr. Cohn and any other person pursuant to which Mr. Cohn was appointed as a director, other than with respect to the matters referred to in Item 1.01 of this Current Report on Form8-K. Mr. Cohn does not have any family relationships with any of Synopsys’ directors or executive officers, or any direct or indirect material interest in any transaction or proposed transaction required to be reported under Section 404(a) of Regulation S-K. As a non-employeedirector, Mr. Cohn is entitled to receive the compensation provided for under Synopsys’ non-employeedirector compensation program as described under the heading “Director Compensation” in Synopsys’ definitive proxy statement filed with the Securities and Exchange Commission on February 19, 2026, which description is incorporated herein by reference. Additionally, in accordance with Synopsys’ customary practice, Synopsys is entering into its standard form of indemnification agreement with Mr. Cohn, which requires Synopsys to indemnify Mr. Cohn against certain liabilities that may arise as a result of his status or service as a director. The description of Mr. Cohn’s indemnification agreement is qualified in its entirety by the full text of the form of indemnification agreement, which is attached to Synopsys’ Form8-Kfiled on July 14, 2011 as Exhibit 99.2.

Item 7.01. Regulation FD Disclosure. A copy of the press release announcing the appointment of Mr. Cohn to the Board is attached as Exhibit 99.1 to this Current Report on Form8-K. The information included in this Current Report on Form8-K(including Exhibit 99.1) is furnished pursuant to Item 7.01 of Form8-Kand shall not be deemed “filed” for the purposes of Section 18 of the Exchange Act, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any filing made by Synopsys under the Exchange Act or the Securities Act of 1933, as amended, except as shall be expressly set forth by specific reference in such a filing. Exhibit Description Number 10.1 Cooperation Agreement, by and among Elliott Investment Management L. P., Elliott Associates, L. P., Elliott International, L. P. and Synopsys, Inc., dated as of May 26, 2026. 99.1 Press Release dated May 27, 2026 announcing the appointment of Jesse Cohn to the Board of Directors of Synopsys, Inc. ─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── 104 Cover Page Interactive Data File (formatted as Inline XBRL). SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, hereunto duly authorized. SYNOPSYS, INC. Dated: May 27, 2026 By: / S / J ANET L EE Janet Lee General Counsel and Corporate Secretary