root@generate-random:~/bcrypt-hashes$ _

Bcrypt Hash Generator

Generate secure bcrypt hashes with configurable rounds for password hashing

[ Bcrypt Hashes - Quick Summary ]

What: Generate secure bcrypt password hashes with configurable work factor/cost (4-12 rounds). Based on Blowfish cipher with built-in automatic salt generation and key stretching. Each round doubles computation time, providing adaptive security as hardware improves. Format: $2y$[rounds]$[22-char-salt][31-char-hash].

When to use: Password storage testing in authentication systems, developing user registration/login flows, testing password verification functions, security research on timing attacks, migration planning for production deployments. Bcrypt is industry-standard for password hashing - superior to raw SHA-256/MD5.

Example: $2y$10$N9qo8uLOickgx2ZMRZoMyeIjZAgcfl7p92ldGxad68LJZdL17lhWy (10 rounds, ~0.6s computation)

Security/Important: FOR TESTING ONLY. Use 10-12 rounds for production (10 rounds ~0.6s, 12 rounds ~2.4s). Same password produces different hashes due to automatic unique salt generation (correct security behavior). Verify with password_verify() which extracts salt from hash. Bcrypt auto-handles salting - no separate salt needed. Maximum 72 character passwords (Blowfish limitation). Each increment in rounds doubles time. Bcrypt > raw hashes (SHA/MD5) for passwords. Consider Argon2 for maximum security (newer standard). Store hashes server-side, never client-side.

Our bcrypt hash generator helps you generate secure password hashes using the bcrypt algorithm with configurable cost factors (rounds). Generate-Random.org provides a free bcrypt generator that creates bcrypt hashes from your text or generates hashes of random data. This password hashing tool uses industry-standard bcrypt with built-in salt generation and key stretching. Generate up to 25 bcrypt hashes at once with configurable rounds (4-12) for performance vs security trade-offs. Perfect for password storage testing, authentication system development, and secure hashing applications. All hashes generated using PHP's password_hash() function with PASSWORD_BCRYPT. No signup required, completely free.

What is a Bcrypt Hash Generator?

A Bcrypt Hash Generator creates secure password hashes using the bcrypt algorithm, which is specifically designed for password storage. Unlike simple hash functions like MD5 or SHA-256, bcrypt includes built-in salt generation and key stretching (via configurable rounds), making it resistant to rainbow table and brute-force attacks.

Bcrypt is based on the Blowfish cipher and uses a cost factor (rounds) to control computational difficulty. Each increase in rounds doubles the time required to compute the hash, providing future-proofing as computing power increases. The output format is $2y$[cost]$[22-char-salt][31-char-hash], where the salt and hash are Base64-encoded. For password generation, check our password generator.

Bcrypt Generator Configuration Options

Input Text (Optional)

Enter custom text to hash (like a test password), or leave empty to hash cryptographically secure random data. When empty, each hash uses unique random bytes as input. When provided, the same text will produce different hashes due to bcrypt's automatic salt generation (this is a security feature—same password should produce different hashes). Supports up to 10,000 characters, though passwords longer than 72 characters are truncated by bcrypt's design.

Rounds / Cost Factor (4-12)

The computational cost factor determining hash generation time. Each increment doubles the time required. 4 rounds: Very fast, only for testing (~0.01s) 6 rounds: Fast, development only (~0.04s) 8 rounds: Moderate, minimum for production (~0.15s) 10 rounds: Recommended default (~0.6s) 12 rounds: Maximum security, high-value accounts (~2.4s) Higher values are more secure but slower. We limit to 12 for performance. Production systems typically use 10-12.

Count (1-25 Hashes)

Generate between 1 and 25 bcrypt hashes in a single batch. When input text is provided, each hash will be different due to automatic salt generation (this is correct behavior). When input is empty, each hash uses unique random data. Useful for bulk password hashing tests or comparing multiple hash outputs.

Include Input Text

Show the input text alongside each hash in the output. Essential for testing password verification (you need to know both the password and hash to test verification). When enabled, export formats include both input and hash columns. Recommended for development and testing workflows.

How to Generate Bcrypt Hashes

[STEP 1] Choose Input

Enter custom text (like a test password), or leave empty to generate bcrypt hashes of random data.

[STEP 1] Select Rounds

Choose cost factor: 10 rounds for standard security, 12 for high security, or lower values for testing only.

[STEP 1] Configure Options

Set quantity (1-25) and enable "Include Input" to see both password and hash together for testing.

[STEP 1] Generate & Export

Click generate and export results in TXT, CSV, or JSON format with full bcrypt metadata included.

Common Use Cases for Bcrypt Hashes

_ Password Storage: Hash user passwords before storing in databases (bcrypt is industry standard)
_ Authentication Testing: Generate test password hashes for authentication system development
_ Security Research: Study password hashing and timing attacks with different cost factors
_ Migration Planning: Test bcrypt performance with different rounds before production deployment
_ Verification Testing: Generate known password/hash pairs for testing verification functions
_ API Development: Create test hashes for password-based authentication API endpoints

Technical Details: Bcrypt Algorithm

Our bcrypt generator uses PHP's password_hash() function with PASSWORD_BCRYPT algorithm. Bcrypt automatically generates a unique salt for each hash and includes it in the output format. The algorithm applies the Blowfish cipher 2^rounds times, creating significant computational cost that grows exponentially with the rounds parameter.

// Bcrypt Hash Generation Process
Input: text (optional), rounds (4-12), count

For each hash i from 1 to count:
  1. If text provided:
     - Use text as input (max 72 chars effective)
  2. Else:
     - Generate 32 bytes of CSPRNG random data

  3. Generate bcrypt hash:
     - Algorithm: PASSWORD_BCRYPT (based on Blowfish)
     - Auto-generate random 16-byte salt
     - Apply cost factor: 2^rounds iterations
     - Encode salt + hash in Base64

  4. Output format: $2y$[rounds]$[salt][hash]
     - $2y$: Bcrypt identifier (PHP version)
     - [rounds]: 2-digit cost factor (04-12)
     - [salt]: 22-char Base64-encoded salt
     - [hash]: 31-char Base64-encoded hash

Properties:
- Salt: Automatically generated and included in output
- Deterministic: Same password + salt = same hash
- One-way: Cannot reverse hash to get password
- Adaptive: Cost factor increases over time as hardware improves
- Resistant: Protects against rainbow tables and brute force

Timing (approximate, hardware dependent):
- 4 rounds:  ~0.01s (testing only)
- 6 rounds:  ~0.04s (development)
- 8 rounds:  ~0.15s (minimum production)
- 10 rounds: ~0.6s (recommended)
- 12 rounds: ~2.4s (maximum security)

Security Notes:
- Each round doubles computation time
- 10+ rounds recommended for production
- Bcrypt > raw hashes (MD5/SHA) for passwords
- Consider Argon2 for maximum security (newer standard)

API Access for Developers

GET https://generate-random.org/api/v1/generate/bcrypt-hashes

VIEW FULL API DOCUMENTATION →

Frequently Asked Questions

What are bcrypt rounds and how do I choose the right value? ▶

Bcrypt rounds (cost factor) control how computationally expensive the hash is to generate. Each increment doubles the time. Use 10-12 rounds for production password storage (recommended), 8 rounds minimum, and lower values only for testing. Higher rounds are more secure against brute-force attacks but slower for your application.

Why do I get different bcrypt hashes for the same password? ▶

This is correct behavior! Bcrypt automatically generates a unique random salt for each hash. The same password will produce different hashes, which is a security feature preventing rainbow table attacks. To verify a password, use password_verify() which extracts the salt from the hash.

Is bcrypt better than SHA-256 for passwords? ▶

Yes! Bcrypt is specifically designed for password hashing with built-in salting and key stretching. SHA-256 is fast (bad for passwords) and requires manual salt management. Bcrypt is slow by design (good for passwords) and handles salting automatically. Always use bcrypt, scrypt, or Argon2 for passwords—never raw SHA-256 or MD5.

Can I use bcrypt hashes generated here in my application? ▶

Yes, but these are primarily for testing and development. The hashes are valid bcrypt hashes compatible with password_verify() in PHP, bcrypt.compare() in Node.js, and similar functions in other languages. For production, generate hashes server-side with your application code, not via a web generator.

What does the bcrypt output format mean? ▶

Bcrypt format: $2y$10$saltsaltsaltsaltsaltXXhashhashhashhashhashhash. $2y$ identifies PHP's bcrypt version, 10 is the rounds, next 22 characters are the Base64-encoded salt, last 31 characters are the Base64-encoded hash. The salt is stored with the hash so password_verify() can recreate the same hash for comparison.

[ HOW TO CITE THIS PAGE ]

APA Style:
Generate-Random.org. (2025). Bcrypt Hash Generator. Retrieved from https://generate-random.org/bcrypt-hashes

Web Citation:
Bcrypt Hash Generator - Generate-Random.org (https://generate-random.org/bcrypt-hashes)