Bcrypt Hash Generator & Verifier – Online

What is a Bcrypt Hash?

Bcrypt is an adaptive, one-way password hashing function based on the Blowfish cipher. “One-way” means it is hashing, not encryption — there is no key that turns the hash back into the original password. Every hash embeds a randomly generated salt — which is why a proper bcrypt generator with salt gives two users with the same password completely different hashes, defeating rainbow tables and precomputed-hash attacks.

The “adaptive” part is the cost factor (also called work factor or salt rounds). It controls how many times the underlying key schedule is applied — each increment doubles the work required. As hardware gets faster, you raise the cost factor to keep brute-force attacks expensive, without changing anything else. Because bcrypt is deliberately slow, it is well suited to password storage and a poor fit for general-purpose checksums.

How to Use This Bcrypt Generator

Whether you need a quick bcrypt password generator for a seed account or want to check a bcrypt hash online, both flows take seconds and never leave your browser.

Generate a hash

1. Type or paste the plaintext value into the Generate panel.
2. Pick a cost factor (4–15). The default of 12 is a sensible baseline.
3. Click Generate Hash and wait for the result — higher cost factors take longer.
4. Use the Copy button to grab the resulting hash.

Verify a hash

1. Paste the plaintext value into the Verify panel.
2. Paste the existing bcrypt hash (starts with $2a$, $2b$, or $2y$).
3. Click Verify — you'll see a clear match or no-match result.

Choosing a Cost Factor

Higher cost factors are slower and more resistant to brute-force attacks — each step up doubles the hashing time. In 2026, 12 is the practical minimum, with 13–14 preferred for new systems. Remember that this tool runs in your browser on a single thread, so very high values can take several seconds; your server hardware will usually be faster.

Security Note

Bcrypt vs Modern Alternatives

Bcrypt is battle-tested, widely supported, and perfectly acceptable at a cost factor of 12 or higher. It does have two well-known limitations: it is not memory-hard (so it offers less protection against GPU/ASIC attacks than newer designs), and it silently truncates input beyond 72 bytes — anything past that is ignored, which can surprise you with long passphrases. For these reasons, OWASP now recommends Argon2id for brand-new systems, as it is memory-hard and tunable across time, memory, and parallelism. Bcrypt remains a solid choice for existing systems and is far better than fast hashes like MD5 or SHA-256 for storing passwords.

Frequently Asked Questions