Can I use this free bcrypt hash generator online without installing anything?

Yes. It is free, no signup, and the bcrypt algorithm runs as TypeScript in the page, so there is no library, command line or server to set up. Type a password, pick a cost and press Generate Hash. It also works offline once the page has loaded, and the same page verifies a password against a hash in Verify mode.

Why does the page freeze when I raise the cost factor?

Hashing runs on the page itself, so the tab stops responding until the hash is done, and every cost step doubles the wait. The estimate under the slider shows the scale: about 1.6 s at cost 14, 1.7 min at cost 20 and far longer near 31. The estimate assumes a typical laptop, so a phone is slower. For a test hash, stay at 10 to 12, and generate production hashes on your server.

What cost factor should I use?

Use the highest cost your login flow can tolerate without an annoying delay, which for most 2020s servers lands at cost 10 to 12. The rule of thumb from OWASP is that a single hash should take roughly a quarter of a second on your production hardware. Cost 12 is about four times slower than cost 10, so measure on your own server rather than copying a number, and raise it every few years as hardware speeds up.

Why does the same password give a different hash each time?

Because bcrypt generates a new random salt for every hash, and the salt is mixed into the result. This is a feature, not a bug: it means two users who both choose the same password still get different hashes, so an attacker cannot spot shared passwords or reuse a precomputed table. Verification still works because the salt is stored inside the hash string itself.

How do I verify a password against a bcrypt hash?

Switch this tool to Verify mode, paste the bcrypt hash, and type the candidate password. The tool reads the cost and salt out of the hash, recomputes the digest with that exact salt, and compares. In your own code you never compare hashes by hand; you call the library verify function such as password_verify in PHP or bcrypt.compare in Node, which does the same recompute-and-compare.

Why does Verify say the hash is not valid?

The hash is not in the shape the verifier accepts. A copy that lost a character, or picked up a quote mark, returns "That does not look like a bcrypt hash." because a bcrypt hash must be exactly 60 characters of the form $2b$10$ plus 53 characters. The rare $2x$ prefix fails with "Invalid salt revision". Leading and trailing spaces are trimmed, so they are not the problem.

Is bcrypt still secure in 2026, or should I use Argon2?

Bcrypt is still considered secure for password storage and remains a recommended option in the OWASP Password Storage Cheat Sheet. Argon2id is the newer winner of the 2015 Password Hashing Competition and is preferred for new systems where you control the runtime, because it also resists GPU and memory-hardware attacks. Bcrypt is a perfectly sound choice, especially when your framework ships it as the default; the mistake to avoid is a fast general-purpose hash like plain SHA-256.

What is the 72-byte limit and does it matter?

Bcrypt only reads the first 72 bytes of the password, so any characters past that are silently ignored. For normal passwords this never matters, but it does mean a very long passphrase can be truncated, and it is why some systems pre-hash the password with SHA-256 before bcrypt. This tool warns you whenever your input exceeds 72 UTF-8 bytes so the truncation is never a surprise.

What do the $2a$, $2b$, and $2y$ prefixes mean?

They are version tags for the bcrypt output format. $2a$ was the original, $2y$ was a PHP-specific fix for a sign-extension bug, and $2b$ is the current corrected OpenBSD version. For new hashes $2b$ is the right prefix, which is what this tool produces. All three verify identically for ASCII passwords; the differences only surface with certain non-ASCII bytes at the 72-byte boundary.

Can a bcrypt hash be reversed back to the password?

No. Bcrypt is a one-way function, so there is no mathematical way to turn a hash back into the original password. The only attack is guessing: an attacker hashes candidate passwords with the same salt and cost and checks for a match. That is exactly why the cost factor matters, because it sets how expensive each guess is. Strong, unique passwords plus a high cost make guessing impractical.

Is bcrypt the same as encryption?

No. Encryption is reversible with a key, so encrypted data can be decrypted back to the original. Hashing with bcrypt is one-way and deliberately slow, and it is meant for verification only: you never need to recover the password, only to confirm someone typed the right one. Storing passwords with encryption instead of hashing is a security anti-pattern, because whoever holds the key can recover every password.

Bcrypt Generator

Generate and verify bcrypt password hashes in the browser with an adjustable cost factor

Password

Cost factor: 1010

Approx. 100 ms per hash. Higher cost is slower to crack, and slower on every login. Cost 10 to 12 is the common production range.

Hashing and verification run entirely in your browser. Nothing you type is sent to a server.

Category:security

Mode:Offline

Version:1.0.0

Access:Free

What is a Bcrypt Generator?

A bcrypt generator turns a plain password into a bcrypt hash: a 60-character string that safely stores the password without keeping the password itself. Bcrypt is a password-hashing function designed by Niels Provos and David Mazieres in 1999, built on the Blowfish cipher, and it is still the default choice in frameworks like Laravel, Spring Security, and Django (as one of several supported hashers). This tool generates a hash from any password and, in verify mode, checks whether a password matches a hash you already have.

Bcrypt does two things that a raw SHA-256 does not. It salts every hash with 16 random bytes baked into the output, so two users with the same password get different hashes and precomputed rainbow tables are useless. And it is deliberately slow: a cost factor from 4 to 31 controls how many key-expansion rounds run, doubling the work with every step. That slowness is the whole point. A fast hash lets an attacker with a leaked database try billions of guesses a second on a GPU; a cost-12 bcrypt hash takes a fifth of a second or so of CPU time, which caps an attacker at a handful of guesses a second per core, which is what keeps a stolen database from turning into a list of plaintext passwords overnight.

The output format is self-describing. A hash like $2b$12$R9h/cIPz0gi.URNNX3kh2OPST9/PgBkqquzi.Ss7KIUgO2t0jWMUW packs four fields separated by dollar signs: the version (2b), the cost (12), and then a 22-character Base64 salt followed by the 31-character digest. Because the salt and cost travel inside the hash, verification needs nothing but the password and the hash string, which is exactly what the verify mode here uses.

Everything runs client-side in your browser. The password you type, the hash you paste, and the salt that gets generated never leave the tab, hit no server, and land in no log. The Network panel of your developer tools shows the only requests are a usage check and a usage record, which carry the cost setting but never the password or hash. The bcrypt algorithm is implemented in pure TypeScript, so the tool also works offline once the page has loaded. The output is byte-for-byte compatible with OpenBSD, PHP password_hash(PASSWORD_BCRYPT), Node bcrypt libraries, and the bcrypt verifiers in every major framework, so a hash generated here validates in your application and vice versa.

A quick way to try the bcrypt hash generator is the sample. In Generate, press Load Sample to fill in correct horse battery staple, leave the cost factor at 10, and press Generate Hash. You get a 60-character string starting $2b$10$, and pressing Generate Hash again gives a different one, because the salt is new each time. In Verify, Load Sample fills a stored hash and the same password, and Verify reports Match (cost 10). Change the first letter to a capital C and it reports No match. That round trip is what a bcrypt password generator should prove.

How to use the Bcrypt Generator?

Enter a password

Type or paste the password you want to hash. Bcrypt uses the first 72 bytes of the UTF-8 encoded password, so anything longer is truncated; the tool warns you when that happens.

Choose a cost factor

Pick a cost from 4 to 31 with the slider. Each step doubles the hashing time. Cost 10 to 12 is the common range for production login systems in the 2020s; higher costs are more resistant to cracking but slower on every legitimate login too.

Generate the hash

Click Generate. A fresh random 16-byte salt is created and the bcrypt hash is computed in your browser. Because the salt is random, hashing the same password again produces a different hash, which is expected and correct.

Copy it, or switch to Verify

Copy the 60-character hash into your user table or config. To check a password against an existing hash, switch to Verify mode, paste the hash and the candidate password, and the tool reports match or no match using the cost and salt embedded in the hash.

Key Features

Generate and Verify

Hash a new password or check a password against an existing bcrypt hash, both in one tool

Adjustable Cost Factor

Slider from cost 4 to 31 with a live estimate of how the work grows as you raise it

Random Salt Every Time

A cryptographically strong 16-byte salt is generated per hash using the Web Crypto API

Standard-Compatible Output

Produces the $2b$ format that OpenBSD, PHP password_hash, Laravel, and Node bcrypt all accept

Frequently Asked Questions

Yes, because the hashing happens entirely in your browser and the password is never sent anywhere. You can verify this in the Network tab of your developer tools: generating a hash makes only a usage check and a usage record, and neither contains the password, the salt or the hash. That said, a browser tab is not a password manager, so avoid pasting the live credentials of a production account into any web page you did not build, and close the tab when you are done.

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Learn more

Read the full Bcrypt Generator guide

Command Palette

Bcrypt Generator

What is a Bcrypt Generator?

How to use the Bcrypt Generator?

Enter a password

Choose a cost factor

Generate the hash

Copy it, or switch to Verify

Key Features

Generate and Verify

Adjustable Cost Factor

Random Salt Every Time

Standard-Compatible Output

Frequently Asked Questions

Related Tools

Hash Generator

JWT Decoder

Password Generator

Password Strength Checker

Comments

Learn more