Annual report pursuant to Section 13 and 15(d)


Cover - USD ($)
12 Months Ended
Dec. 31, 2021
Feb. 10, 2022
Jun. 30, 2021
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2021    
Current Fiscal Year End Date --12-31    
Document Transition Report false    
Entity File Number 001-38160    
Entity Registrant Name Redfin Corporation    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 74-3064240    
Entity Address, Address Line One 1099 Stewart Street    
Entity Address, Address Line Two Suite 600    
Entity Address, City or Town Seattle    
Entity Address, State or Province WA    
Entity Address, Postal Zip Code 98101    
City Area Code (206)    
Local Phone Number 576-8333    
Title of 12(b) Security Common Stock, $0.001 par value per share    
Trading Symbol RDFN    
Security Exchange Name NASDAQ    
Entity Well Known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag true    
Entity Shell Company false    
Entity Public Float     $ 6,440,535,375
Entity Common Stock, Shares Outstanding   106,396,652  
Documents Incorporated by Reference The portions of the registrant's proxy statement to be filed in connection with the registrant’s 2022 Annual Meeting of Stockholders that are responsive to the disclosure required by Part III of Form 10-K are incorporated by reference into Part III of this Form 10-K.    
Entity Central Index Key 0001382821    
Document Fiscal Year Focus 2021    
Document Fiscal Period Focus FY    
Amendment Flag false