Bcrypt Hash Generator - Generate and Verify Bcrypt Hashes Online

What is the Bcrypt Generator?

The Bcrypt Generator is a free online tool that creates bcrypt password hashes and verifies plain text against existing bcrypt hashes. Bcrypt is a widely trusted password hashing algorithm designed specifically for secure password storage. It incorporates a salt to protect against rainbow table attacks and is intentionally slow to resist brute-force attempts.

This tool performs all hashing and verification client-side in your browser using the bcryptjs library. Your passwords never leave your device, ensuring complete privacy. You can adjust the salt rounds (cost factor) to balance security with performance.

For other hashing algorithms, try our MD5 Hash Generator, SHA256 Hash Generator, or SHA512 Hash Generator. For generating secure passwords to hash, use the Password Generator.

How to Use the Bcrypt Generator

This tool provides two main functions in a two-column layout:

Generate a Bcrypt Hash

Enter your text or password in the String to Hash input field.
Adjust the Salt Rounds (4-12 recommended; higher values are more secure but slower).
The bcrypt hash is generated automatically and displayed in the output card.
Click Copy Hash to copy the hash to your clipboard.

Verify a Bcrypt Hash

Enter the plain text you want to verify in the String to Verify field.
Paste a bcrypt hash into the Bcrypt Hash field.
The tool instantly checks if they match and displays the result in green (match) or red (no match).

Understanding Salt Rounds

The salt rounds (also called the cost factor) determine how computationally expensive the hashing process is. Each increment doubles the time required. Here is a general guideline:

4-6 rounds: Fast but less secure. Suitable for low-risk applications.
8-12 rounds: Balanced performance and security. Recommended for most web applications.
13+ rounds: Very secure but may cause noticeable delays on slower devices.

In practice, modern applications typically use 10-12 rounds. The OWASP Foundation recommends choosing a work factor that results in approximately 500ms hashing time on your target hardware.

How Bcrypt Differs from Other Hash Algorithms

Unlike general-purpose hash functions like MD5 or SHA-256, bcrypt is specifically designed for password hashing. Key differences include:

Built-in salting: Bcrypt automatically generates and stores a unique random salt with each hash.
Adaptive cost factor: You can increase the work factor as hardware improves over time.
Slow by design: Bcrypt intentionally uses significant computational resources to resist brute-force attacks.
Fixed output length: All bcrypt hashes are exactly 60 characters long regardless of input size.

Frequently Asked Questions

What is bcrypt?

Bcrypt is a password hashing function based on the Blowfish cipher, designed by Niels Provos and David Mazieres in 1999. It is one of the most widely used password hashing algorithms and includes built-in salting and configurable cost parameters to adapt to increasing hardware capabilities.

Is bcrypt safe for password storage?

Yes, bcrypt is considered very safe for password storage when used with an appropriate salt round count (10+). Its deliberate slowness and built-in salting make it resistant to brute-force, rainbow table, and dictionary attacks. However, for new applications, Argon2 (the winner of the Password Hashing Competition) is now recommended over bcrypt.

Why do bcrypt hashes start with $2a$, $2b$, or $2y$?

The prefix indicates the bcrypt version: $2a$ was the original, $2b$ fixed a minor bug with certain Unicode inputs (February 2014), and $2y$ was a vendor-specific fix adopted by some implementations. Our tool generates $2a$ hashes using the bcryptjs library, which is consistent with the standard bcrypt specification.

What happens if I increase the salt rounds too high?

Higher salt rounds increase hashing time exponentially. At very high values (like 20+), hashing can take several seconds even on fast machines. This could lead to a poor user experience in production applications where passwords need to be verified for every login. Most developers use 10-12 rounds as a balance.

Can I use this tool to verify if a password matches a stored hash?

Yes, use the Verify Hash section. Enter the password you want to check and paste the stored bcrypt hash. The tool will instantly tell you if they match. This is useful for testing authentication logic or verifying that your password hashing implementation is working correctly.

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Bcrypt Generator