Cover Page	3 Months Ended
	Apr. 30, 2020 shares
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Apr. 30, 2020
Document Transition Report	false
Entity File Number	001-38044
Entity Registrant Name	Okta, Inc.
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	100 First Street, Suite 600
Entity Tax Identification Number	26-4175727
Entity Address, City or Town	San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94105
City Area Code	888
Local Phone Number	722-7871
Title of 12(b) Security	Class A common stock, par value $0.0001 per share
Trading Symbol	OKTA
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Smaller Reporting Company	false
Emerging Growth Company	false
Entity Shell Company	false
Amendment Flag	false
Entity Central Index Key	0001660134
Current Fiscal Year End Date	--01-31
Document Fiscal Year Focus	2021
Document Period Focus	Q1
Class A Common Stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding	116,135,161
Class B Common Stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding	8,474,062