Document And Entity Information - USD ($)	12 Months Ended
	Sep. 30, 2021	Nov. 19, 2021	Mar. 31, 2021
Document Information [Line Items]
Entity Central Index Key	0000924383
Entity Registrant Name	Genasys Inc.
Amendment Flag	false
Current Fiscal Year End Date	--09-30
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2021
Document Type	10-K
Document Annual Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Entity File Number	0-24248
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	87-0361799
Entity Address, Address Line One	16262 West Bernardo Drive
Entity Address, City or Town	San Diego
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92127
City Area Code	858
Local Phone Number	676-1112
Title of 12(b) Security	Common stock, $0.00001 par value per share
Trading Symbol	GNSS
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Small Business	true
Entity Filer Category	Non-accelerated Filer
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 191,676,200
Entity Common Stock, Shares Outstanding		36,482,197