Bcrypt Hash Generator
Generate bcrypt hashes with configurable cost factor (4–31). Auto-salted, rainbow-table resistant, fully browser-based. Recommended for secure password storage.
bcrypt is a password-hashing function designed by Niels Provos and David Mazières in 1999. It embeds a random salt and a cost factor, making brute-force attacks computationally expensive. Unlike MD5 or SHA-256, bcrypt hashes cannot be reversed via rainbow tables. Use it for all password storage. Higher cost factors produce slower hashes — cost 10 is the industry default, balancing security and performance.
How to use Bcrypt Hash Generator
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Open the Generate tab
The 'Generate' tab is active by default on this page.
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Enter your password
Type or paste the password you want to hash into the input field.
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Choose a cost factor
Select a cost factor from 4 to 31. Cost 10 is the OWASP minimum for production; cost 12 provides stronger protection for new systems.
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Wait for hashing to complete
Hashing takes 300 ms at cost 10, up to several seconds at higher factors. A progress indicator is shown while bcryptjs works.
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Copy the bcrypt hash
Click Copy to copy the full $2b$-prefixed hash for use in your database or config file.
Bcrypt Hash Generator FAQ
What is bcrypt and why use it for password storage?
What cost factor should I use?
Does bcrypt output change every time?
Is this tool safe to use with real passwords?
Are my inputs sent to a server?
What does the $2b$ prefix mean?
Is bcrypt still recommended in 2025?
How does bcrypt compare to PBKDF2 and Argon2?
Can bcrypt hashes be verified with this tool?
Background
Generate bcrypt hashes with a configurable cost factor, entirely in your browser using the bcryptjs library.
Why bcrypt for passwords? Unlike MD5 or SHA-256, bcrypt was designed specifically for password storage:
- Random salt included — every hash is unique, preventing rainbow table attacks even if two users share the same password
- Tunable work factor — increase the cost factor as hardware gets faster to maintain the same level of protection over time
- Intentionally slow — each verification costs time, making brute-force and credential-stuffing attacks computationally expensive
Cost factor guide:
- 4 — ~1 ms, development and testing only
- 10 — ~300 ms, OWASP minimum recommendation for production
- 12 — ~1.2 s, recommended for new systems in 2025
- 14+ — use for high-value accounts where latency is acceptable
Output format: $2b$<cost>$<22-char salt><31-char hash> — the algorithm
version, cost factor, salt, and hash are all embedded in a single 60-character
string. Store the entire string; no separate salt column needed.
All hashing runs client-side. Nothing is uploaded to any server.
Related tools
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