PrivTab

Bcrypt Generator & Checker

Hash a password with bcrypt for a test user or a seed file, or find out which password a hash belongs to when you have a guess.

Runs in your browser · No uploads

What do you want to do?

Each step up doubles the time. 10 to 12 is usual for websites today.

  • Nothing leaves your device
  • No server-imposed size limits
  • No sign-up, no watermark
  • Free

How to use the bcrypt generator

  1. Choose to make a hash or to check one.
  2. Type the password, and the hash when checking.
  3. Copy the hash, or read whether they match.

Good to know

  • Hashes start with $2b$, the current version. Hashes starting with $2a$ and $2y$ (PHP) can be checked too.
  • The cost is the number of rounds as a power of 2: each step up doubles the time it takes to make and to check a hash, for you and for an attacker. 10 to 12 is usual for websites.
  • Each hash gets a new random salt, so the same password gives a different hash every time. All of them check correctly.
  • bcrypt uses only the first 72 bytes of a password; the page warns when a password is longer.

Your passwords stay on your device

Hashing and checking run in your browser with bcrypt.js. Nothing you type is sent anywhere.

Frequently asked questions

Can a bcrypt hash be turned back into the password?

No. bcrypt is one-way: the only way to find the password is to try candidates, which the cost makes slow on purpose. That is why you can check a guess here but not "decrypt" a hash.

Is my password sent anywhere?

No. The hash is made in your browser, and this site's security policy blocks the page from sending anything.