Cover - shares	9 Months Ended
	Sep. 29, 2023	Oct. 30, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 29, 2023
Document Transition Report	false
Entity File Number	000-25826
Entity Registrant Name	HARMONIC INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	77-0201147
Entity Address, Address Line One	2590 Orchard Parkway
Entity Address, City or Town	San Jose
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	95131
City Area Code	408
Local Phone Number	542-2500
Title of 12(b) Security	Common stock, $0.001 par value
Trading Symbol	HLIT
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		112,189,931
Amendment Flag	false
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Entity Central Index Key	0000851310
Current Fiscal Year End Date	--12-31