Cover - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Feb. 29, 2024	Jun. 30, 2023
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2023
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-40276
Entity Registrant Name	Semrush Holdings, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	84-4053265
Entity Address, Address Line One	800 Boylston Street, Suite 2475
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02199
City Area Code	(800)
Local Phone Number	851-9959
Title of 12(b) Security	Class A Common Stock, $0.00001 par value per share
Trading Symbol	SEMR
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
ICFR Auditor Attestation Flag	false
Document Financial Statement Error Correction	false
Entity Shell Company	false
Entity Public Float			$ 314.1
Documents Incorporated by Reference	Portions of the registrant's definitive Proxy Statement for the 2024 Annual Meeting of Stockholders are incorporated herein by reference in Part III of this Annual Report on Form 10-K to the extent stated herein. Such Proxy Statement will be filed with the Securities and Exchange Commission within 120 days of the registrant's fiscal year ended December 31, 2023.
Amendment Flag	false
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Entity Central Index Key	0001831840
Common Class A
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		121,084,403
Class B Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		23,482,057