v3.19.1
Document and Entity Information - USD ($)
$ in Billions
12 Months Ended
Jan. 31, 2019
Feb. 28, 2019
Jul. 31, 2018
Entity Information [Line Items]      
Document Type 10-K    
Document Period End Date Jan. 31, 2019    
Amendment Flag false    
Entity Registrant Name Okta, Inc.    
Entity Central Index Key 0001660134    
Current Fiscal Year End Date --01-31    
Entity Filer Category Large Accelerated Filer    
Document Fiscal Year Focus 2019    
Document Period Focus FY    
Entity Well-Known Seasoned Issuer Yes    
Smaller Reporting Company false    
Emerging Growth Company false    
Shell Company false    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Public Float     $ 4.7
Class A Common Stock      
Entity Information [Line Items]      
Entity Common Stock, Shares Outstanding   101,267,377  
Class B Common Stock      
Entity Information [Line Items]      
Entity Common Stock, Shares Outstanding   10,957,938