Interesting, how many hashes does it take generally?  I do offload to the event loop to check for cancellation events and other things, which is probably making it slower, I guess I should reduce the checks. To very rare.  

 To once every million hashes probably, right now it does it every 10k hashes 

 oh wait are you using any workers or just doing the hashing on the main thread? 

 Main thread, it was easier, thought I'd move to workers after the first iterstion 

 oh true, you should probably do that. it’s pretty easy https://github.com/smolgrrr/Wired/blob/main/client/src/components/forms/handleSubmit.ts https://github.com/smolgrrr/Wired/blob/main/client/src/powWorker.ts