Document and Entity Information - shares	3 Months Ended
	Apr. 30, 2017	May 31, 2017
Entity Information [Line Items]
Document Type	10-Q
Document Period End Date	Apr. 30, 2017
Amendment Flag	false
Entity Registrant Name	Okta, Inc.
Entity Central Index Key	0001660134
Current Fiscal Year End Date	--01-31
Entity Filer Category	Non-accelerated Filer
Document Fiscal Year Focus	2018
Document Period Focus	Q1
Class A Common Stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		13,373,424
Class B Common Stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		81,912,432