Document and Entity Information - shares	3 Months Ended
	Jan. 31, 2021	Feb. 17, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jan. 31, 2021
Document Transition Report	false
Entity File Number	000-19807
Entity Registrant Name	SYNOPSYS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	56-1546236
Entity Address, Address Line One	690 EAST MIDDLEFIELD ROAD
Entity Address, City or Town	MOUNTAIN VIEW
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94043
City Area Code	650
Local Phone Number	584-5000
Title of 12(b) Security	Common Stock($0.01 par value)
Trading Symbol	SNPS
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		152,373,162
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Entity Central Index Key	0000883241
Current Fiscal Year End Date	--10-31