v3.10.0.1
Document and Entity Information - shares
9 Months Ended
Oct. 31, 2018
Nov. 30, 2018
Entity Information [Line Items]    
Document Type 10-Q  
Document Period End Date Oct. 31, 2018  
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 2019  
Document Period Focus Q3  
Smaller Reporting Company false  
Emerging Growth Company true  
Extended Transition Period true  
Class A Common Stock    
Entity Information [Line Items]    
Entity Common Stock, Shares Outstanding   98,611,070
Class B Common Stock    
Entity Information [Line Items]    
Entity Common Stock, Shares Outstanding   11,827,554