What is the Bcrypt Hash Generator & Verifier?
This tool generates and verifies bcrypt password hashes using the bcryptjs library, letting you pick the cost factor (rounds) and see roughly how long that cost takes to compute on your own machine.
How it works
Generation calls bcrypt's genSaltSync/hashSync with a work factor between 4 and 14; each increment roughly doubles the number of internal rounds, so a cost of 14 takes about 16x longer than a cost of 10. Verification uses compareSync, which re-hashes the candidate plaintext with the salt embedded in the existing hash and checks whether the result matches — the same check a server performs at login.
SysAdmin & security use cases
- Generate a bcrypt hash to seed a test database or fixture without touching a real backend.
- Read the cost factor an existing hash was created with from its $2a$NN$ prefix.
- Verify a plaintext password against a hash pulled from a database dump while debugging a login issue.
- See how much slower a higher cost factor makes hashing before changing it in a production config.