Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2022	Aug. 01, 2022
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
Entity Registrant Name	Aligos Therapeutics, Inc.
Entity Central Index Key	0001799448
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Title of 12(b) Security	Common Stock, par value, $0.0001 per share
Trading Symbol	ALGS
Security Exchange Name	NASDAQ
Entity File Number	001-39617
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-4724808
Entity Address, Address Line One	One Corporate Drive
Entity Address, Address Line Two	2nd Floor
Entity Address, City or Town	South San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94080
City Area Code	800
Local Phone Number	466-6059
Document Quarterly Report	true
Document Transition Report	false
Voting Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		39,717,001
Non-voting Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		3,092,338