Exhibit 32.1

CERTIFICATION OF CHIEF EXECUTIVE OFFICER AND CHIEF FINANCIAL OFFICER

PURSUANT TO 18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report on Form 10-Q of Semrush Holdings, Inc. for the quarterly period ended September 30, 2021 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Oleg Shchegolev, as Principal Executive Officer of Semrush Holdings, Inc., hereby certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that, to the best of my knowledge, the Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended, and the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Semrush Holdings, Inc.

Date:	November 10, 2021	By:	/s/ Oleg Shchegolev
			Oleg Shchegolev
			Chief Executive Officer
			(Principal Executive Officer)

The foregoing certification is being furnished pursuant to 18 U.S.C. Section 1350. It is not being filed for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, and it is not to be incorporated by reference into any filing of the Company, regardless of any general incorporation language in such filing.

In connection with the Quarterly Report on Form 10-Q of Semrush Holdings, Inc. for the quarterly period ended September 30, 2021 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Evgeny Fetisov, as Principal Financial Officer of Semrush Holdings, Inc., hereby certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that, to the best of my knowledge, the Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended, and the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Semrush Holdings, Inc.

Date:	November 10, 2021	By:	/s/ Evgeny Fetisov
			Evgeny Fetisov
			Chief Financial Officer
			(Principal Financial Officer)

The foregoing certification is being furnished pursuant to 18 U.S.C. Section 1350. It is not being filed for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, and it is not to be incorporated by reference into any filing of the Company, regardless of any general incorporation language in such filing.