The Bcrypt Generator lets you hash passwords using the bcrypt algorithm and verify passwords against existing bcrypt hashes — all directly in your browser. Bcrypt is the industry-standard password hashing function designed to be deliberately slow, making brute-force attacks computationally expensive. This tool is essential for developers testing authentication systems, verifying hash outputs during debugging, or learning how bcrypt works. Choose a cost factor between 10 and 12 to balance security and performance. Since all hashing and verification run client-side using the bcryptjs library, your passwords are never transmitted to any server, ensuring complete privacy.
Verify password
Check if a password matches a bcrypt hash.
About Bcrypt
Bcrypt was designed in 1999 by Niels Provos and David Mazières based on the Blowfish cipher. Unlike fast hash functions like SHA-256, bcrypt is intentionally slow and includes a configurable cost factor that determines the number of hashing rounds (2^cost iterations). This makes it resistant to brute-force and rainbow-table attacks even as hardware improves — you simply increase the cost factor. A bcrypt hash includes the algorithm identifier ($2a$ or $2b$), the cost factor, a 22-character salt, and the 31-character hash, all in a single portable string. This tool generates hashes and verifies password-hash pairs using the bcryptjs JavaScript library, running entirely in your browser so your passwords stay on your device.
How to Use Bcrypt Generator
- Hash a password: Enter a password, select a cost factor (10–12), and click Hash password. Copy the resulting bcrypt hash.
- Verify a password: Enter a password and paste a bcrypt hash, then click Verify to check if they match.
- Use the hash in your application's database or configuration for testing purposes.
Key Features
- Generate bcrypt hashes with configurable cost factor (10–12 rounds)
- Verify any password against an existing bcrypt hash
- Automatic salt generation — every hash is unique even for the same password
- 100% browser-based using bcryptjs — no server communication
- Portable hash format compatible with all major frameworks (Laravel, Django, Node.js, etc.)
- Pairs well with our Hash Generator for comparing different hash algorithms
When to Use This Tool
- Testing authentication flows during application development
- Verifying that a stored bcrypt hash matches an expected password
- Generating test hashes for seeding development databases
- Learning how bcrypt's cost factor affects hashing time and security
- Debugging password-related issues without exposing credentials to external services
Technical Details
Bcrypt uses the Blowfish cipher in a key-setup phase that is repeated 2^cost times (e.g., cost 10 = 1,024 iterations, cost 12 = 4,096 iterations). Each hash includes a randomly generated 128-bit salt, making rainbow-table attacks infeasible. The output format is $2b$[cost]$[22-char salt][31-char hash], totaling 60 characters. This tool uses the bcryptjs library, a pure JavaScript implementation that runs in your browser without WebAssembly or server dependencies. For production applications, always hash passwords server-side and never log or transmit plaintext passwords.
Conclusion
The Bcrypt Generator is a secure, browser-based tool for hashing and verifying passwords using the industry-standard bcrypt algorithm. With configurable cost factors and zero server communication, it is ideal for development, testing, and learning about password security.