v3.23.1
Cover Page - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2022
Nov. 23, 2022
Mar. 31, 2022
Cover [Abstract]      
Document Type 10-K/A    
Document Annual Report true    
Document Period End Date Sep. 30, 2022    
Current Fiscal Year End Date --09-30    
Document Transition Report false    
Entity File Number 001-38720    
Entity Registrant Name Twist Bioscience Corporation    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 46-2058888    
Entity Address, Address Line One 681 Gateway Blvd    
Entity Address, City or Town South San Francisco    
Entity Address, State or Province CA    
Entity Address, Postal Zip Code 94080    
City Area Code 800    
Local Phone Number 719-0671    
Title of 12(b) Security Common Stock    
Trading Symbol TWST    
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     $ 2,390
Entity Common Stock, Shares Outstanding   56,568,420  
Documents Incorporated by Reference None.    
Amendment Flag false    
Entity Central Index Key 0001581280    
Document Fiscal Year Focus 2022    
Document Fiscal Period Focus FY