bcrypt Hash Generator and Checker
Make a bcrypt hash at a chosen cost, check a password against an existing hash, and read the version, cost and salt out of one.
Check against a hash
Files are processed in your browser and are never uploaded to a server.
How to use
Free to use with no sign-up, no install and no usage limit.
Type a password and a hash appears at the cost you choose. This is for seeding one admin account by hand, or for checking whether a hash in a config file is the one you think it is.
Every hash of the same password is different, because a fresh salt goes into each one. That is the point of a salt: two users with the same password must not end up with the same stored value, or one cracked hash reveals both.
Cost doubles the work each time it goes up by one. Ten is the common default at roughly a tenth of a second; twelve takes about four times that. Higher is safer against offline cracking and slower for every genuine login, which is the trade you are actually making.
bcrypt only reads the first 72 bytes and silently discards the rest. A long passphrase can therefore collide with a different one sharing the same opening, so you are warned when the input crosses that line. Korean and other multi-byte text reaches it after about 24 characters.
The checker takes an existing hash from anywhere, not just one made here, and reads its version marker, cost and salt. $2y$ usually means it came from PHP, $2a$ from an older library.
Nothing is sent anywhere. A tool that asks for a password and posts it to a server would be worse than useless, so this one runs entirely in the browser.