Argon2 Hash Generator

Generate secure Argon2 password hashes with customizable parameters. The most secure password hashing algorithm recommended by OWASP, NIST, and security experts worldwide.

Military-Grade Security

OWASP Recommended

GPU Resistant

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Hash Generate

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Hash Verify

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Custom Config

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Security Presets

Free Argon2 Hash Generator: Military-Grade Password Security (OWASP & NIST Recommended)

Generate secure Argon2id and Argon2i password hashes with customizable security parameters. Winner of the Password Hashing Competition, OWASP-recommended, and NIST-approved for maximum protection against brute-force attacks, GPU cracking, and side-channel attacks.

What Is Argon2? (And Why It's the Most Secure Password Hashing Algorithm)

Argon2 is a memory-hard password hashing algorithm that won the Password Hashing Competition in 2015 and is now the gold standard for secure password storage. Unlike older algorithms like bcrypt or PBKDF2, Argon2 resists GPU, ASIC, and FPGA cracking attacks by requiring large amounts of memory, making parallel attacks economically unfeasible.

Organizations like OWASP, NIST, and major tech companies recommend Argon2 as the first choice for password hashing. It provides tunable parameters (time cost, memory cost, parallelism) that let you balance security and performance—ensuring passwords remain protected even against future hardware advances.

Why Argon2 Is Superior to Other Password Hashing Algorithms:

Security Advantages

• GPU-resistant: Memory-hard design prevents parallel GPU attacks
• ASIC-resistant: High memory requirements make custom hardware costly
• Side-channel resistant: Argon2i variant defends against timing attacks
• Future-proof: Tunable parameters adapt to hardware improvements

Industry Recognition

• Password Hashing Competition winner (2015)
• OWASP #1 recommendation for password storage
• NIST SP 800-63B approved for federal systems
• Used by 1Password, Bitwarden, and enterprise password managers

Argon2 vs Bcrypt vs PBKDF2 vs Scrypt: Security Comparison

Algorithm	GPU Resistance	Memory Hard	OWASP Status
Argon2id	✓ Excellent	✓ Yes (64MB-1GB)	✓ #1 Choice
Bcrypt	⚠️ Moderate	⚠️ Limited (4KB)	⚠️ Acceptable
PBKDF2	⚠️ Poor	✗ No	⚠️ Legacy Only
Scrypt	✓ Good	✓ Yes	⚠️ Alternative

Bottom Line: Argon2id combines the best of Argon2i (side-channel resistance) and Argon2d (GPU resistance), making it the most secure choice for modern applications. Learn more about Argon2.

How to Generate Argon2 Password Hashes in 3 Simple Steps

Enter your password: Type the password you want to hash in the input field. Use the "Generate Random" button to create a cryptographically secure password with mixed case, numbers, and symbols. Our password strength indicator shows real-time security scoring (Weak, Moderate, Strong, Very Strong).

Choose security level: Select from 4 preset configurations—Low (16MB, fast), Medium (32MB, balanced), High (64MB, recommended), or Paranoid (256MB, maximum security). Advanced users can expand custom configuration to fine-tune time cost (iterations), memory cost (KB), parallelism (threads), key length (bytes), and variant (Argon2id/Argon2i).

Get your PHC-encoded hash: Click "Generate Hash" to receive a complete PHC-format string (e.g., $argon2id$v=19$m=65536,t=3,p=4$...) ready for database storage. The result includes the hash, salt, and all parameters—everything needed for password verification. Copy to clipboard, download as JSON/TXT, or switch to the "Verify Hash" tab to test passwords against existing hashes.

💡 Pro Tip: Choosing the Right Security Level

Use High preset (64MB, 3 iterations) for most production applications—it's the OWASP-recommended default. Increase to Paranoid (256MB) for admin accounts or highly sensitive systems. Test execution time on your server: aim for 0.5-2 seconds per hash to balance security and user experience. Adjust memory/time parameters as hardware improves over time.

Understanding Argon2 Parameters: Complete Guide

Time Cost (Iterations) - Recommended: 3-10

Controls the number of passes over the memory. Higher values = slower hashing = more security against brute-force attacks. Each iteration roughly doubles computation time. OWASP recommendation: 3 iterations minimum. Increase to 5-10 for sensitive applications. Too high values (20+) create poor user experience without proportional security gains.

Example: Time cost of 3 ≈ 100ms | Time cost of 5 ≈ 300ms | Time cost of 10 ≈ 1000ms

Memory Cost (KB) - Recommended: 65536 KB (64 MB)

Specifies memory allocation in kilobytes. This is Argon2's key defense against GPU/ASIC attacks—attackers need proportional memory for each parallel guess, making large-scale attacks prohibitively expensive. OWASP recommendation: 64 MB (65536 KB) minimum. Increase to 128-256 MB for maximum security. Memory cost has the biggest impact on cracking resistance.

Attack Cost Example: 64 MB = $0.50/guess on AWS | 256 MB = $2.00/guess | Makes billion-password attacks financially unfeasible

Parallelism (Threads) - Recommended: 4

Number of parallel threads used during hashing. Higher parallelism enables faster hashing on multi-core CPUs without reducing security. OWASP recommendation: 4 threads. Match your server's CPU cores for optimal performance (e.g., 8 threads on 8-core server). Parallelism affects memory layout and prevents certain optimization attacks.

Performance Tip: 4 threads on quad-core CPU = 4x faster than single-thread | Adjust based on server specs

Key Length (Bytes) - Recommended: 32 bytes (256 bits)

Output hash size in bytes. 32 bytes (256 bits) is standard for cryptographic strength, equivalent to AES-256 encryption. Longer hashes (64, 128 bytes) don't improve security against brute-force but provide collision resistance for extremely large databases (billions of users). Shorter hashes (16 bytes) are weaker and not recommended.

Standard Sizes: 16 bytes = 128-bit | 32 bytes = 256-bit (recommended) | 64 bytes = 512-bit

Variant: Argon2id vs Argon2i vs Argon2d

Argon2id (Recommended): Hybrid variant combining Argon2i and Argon2d. Provides both side-channel attack resistance (from Argon2i) and GPU resistance (from Argon2d). Use for all new applications—it's the OWASP default.

Argon2i: Optimized against side-channel attacks (timing analysis). Slightly slower than Argon2d but safer in environments with untrusted code or shared hardware. Use for maximum paranoia in key derivation.

Argon2d: Maximum resistance to GPU/ASIC attacks but vulnerable to side-channel attacks. Rarely used for password hashing; primarily for cryptocurrency proof-of-work. Not available in many standard libraries.

⚠️ Parameter Tuning Best Practices

Start with OWASP defaults: Argon2id, memory=64MB, time=3, parallelism=4, key_length=32. Measure execution time on your production hardware—target 0.5-2 seconds per hash. If too fast, increase memory cost first (biggest security impact), then time cost. If too slow, reduce time cost or memory cost, but never go below OWASP minimums.

Re-evaluate yearly: As hardware improves (Moore's Law), increase parameters to maintain equivalent security. Tools like libargon2 provide benchmarking utilities to test optimal settings for your infrastructure.

How Password Verification Works with Argon2

Unlike encryption, password hashing is a one-way function—you cannot reverse a hash to get the original password. When a user logs in, you hash their entered password with the same parameters and salt as the stored hash, then compare results. Our tool's "Verify Hash" tab demonstrates this process safely in your browser.

Step-by-Step Verification Process:

1. User submits password during login (e.g., MySecureP@ss123)
2. Retrieve stored PHC-encoded hash from database: $argon2id$v=19$m=65536,t=3,p=4$...
3. Parse hash to extract salt and parameters (memory=65536, time=3, parallelism=4)
4. Re-hash submitted password using extracted parameters and salt
5. Use constant-time comparison to prevent timing attacks: If hashes match → grant access | If hashes differ → deny access

🔒 Security Feature: Constant-Time Comparison

Our verification uses constant-time comparison algorithms that take the same amount of time whether hashes match or not. This prevents timing attacks where attackers measure response times to deduce password characters. Standard string comparison (==) returns early on first mismatch, leaking information. Always use cryptographic comparison functions in production code. Learn about timing attacks.

Common Use Cases for Argon2 Password Hashing

Web Application User Authentication

Hash user passwords during registration, verify during login. Replace legacy bcrypt/PBKDF2 hashes with Argon2 for enhanced security. Frameworks like Django, Laravel, and Spring Security have built-in Argon2 support.

✓ SaaS platforms
✓ E-commerce sites
✓ Social networks
✓ Content management systems

API Keys and Secret Management

Derive encryption keys from user passwords for end-to-end encrypted applications. Generate high-entropy keys for API authentication tokens, database encryption, or hardware security modules (HSMs).

✓ Password managers (1Password, Bitwarden)
✓ Encrypted messaging apps
✓ API key generation
✓ Client-side encryption

Database Credential Protection

Hash database passwords for internal tools, admin panels, and sensitive operations. Protect against SQL injection attacks that expose password hashes—Argon2's memory-hardness makes offline cracking nearly impossible.

✓ Admin account passwords
✓ Service account credentials
✓ Database user passwords
✓ Configuration secrets

Compliance and Regulatory Requirements

Meet password security standards for GDPR, HIPAA, PCI-DSS, SOC 2, and other regulations. Argon2's NIST approval and OWASP recommendation satisfy auditor requirements for "industry-standard cryptographic protection."

✓ Healthcare systems (HIPAA)
✓ Financial services (PCI-DSS)
✓ European services (GDPR)
✓ Federal systems (NIST compliance)

Implementing Argon2 in Your Application (Code Examples)

Most modern programming languages have Argon2 libraries. Below are production-ready examples for popular frameworks. Always use established libraries rather than implementing Argon2 yourself—cryptography is easy to get wrong.

Python (Django/Flask)

argon2-cffi

from argon2 import PasswordHasher ph = PasswordHasher(time_cost=3, memory_cost=65536, parallelism=4) # Hash password hash = ph.hash("user_password") # Store hash in database: $argon2id$v=19$m=65536,t=3,p=4$... # Verify password try: ph.verify(hash, "user_password")  # Returns True if match print("Password correct!") except: print("Password incorrect!")

Install: pip install argon2-cffi | Documentation

Node.js (Express/NestJS)

argon2

const argon2 = require('argon2');

// Hash password
const hash = await argon2.hash('user_password', {
  type: argon2.argon2id,
  memoryCost: 65536,  // 64 MB
  timeCost: 3,
  parallelism: 4
});
// Store hash in database

// Verify password
const isValid = await argon2.verify(hash, 'user_password');
console.log(isValid ? 'Password correct!' : 'Password incorrect!');

Install: npm install argon2 | GitHub Repo

PHP (Laravel/Symfony)

Native (PHP 7.2+)

// Hash password (PHP 7.2+ with libsodium)
$hash = password_hash('user_password', PASSWORD_ARGON2ID, [
    'memory_cost' => 65536,  // 64 MB
    'time_cost' => 3,
    'threads' => 4
]);
// Store $hash in database

// Verify password
if (password_verify('user_password', $hash)) {
    echo "Password correct!";
} else {
    echo "Password incorrect!";
}

Built-in PHP 7.2+ | PHP Documentation

Go (Golang)

golang.org/x/crypto/argon2

import "golang.org/x/crypto/argon2"

// Hash password
salt := make([]byte, 16)
rand.Read(salt)
hash := argon2.IDKey([]byte("user_password"), salt, 3, 65536, 4, 32)

// Encode to PHC format for storage
encoded := fmt.Sprintf("$argon2id$v=19$m=65536,t=3,p=4$%s$%s",
    base64.RawStdEncoding.EncodeToString(salt),
    base64.RawStdEncoding.EncodeToString(hash))

// Verify: Parse encoded hash, extract salt, re-hash, compare

Install: go get golang.org/x/crypto/argon2 | Package Docs

⚡ Performance Optimization Tips

• Async hashing: Run Argon2 in background workers to avoid blocking web requests (can take 0.5-2 seconds)
• Password rehashing: Upgrade weak hashes on user login—verify old hash, generate new Argon2 hash, update database
• Load testing: Benchmark Argon2 under peak load to ensure server handles concurrent hashing without timeout errors
• Parameter migration: Store Argon2 version in PHC string—allows seamless parameter updates as hardware improves

Frequently Asked Questions (FAQ)

Is Argon2 better than bcrypt?

Yes. While bcrypt is still acceptable, Argon2 is superior because it's memory-hard (bcrypt uses only 4KB), provides better GPU resistance, and offers tunable memory parameters that future-proof against hardware advances. OWASP recommends Argon2 as the first choice for new applications. Read expert comparison.

Should I use Argon2id or Argon2i?

Use Argon2id for 99% of use cases—it's the OWASP-recommended variant that combines GPU resistance and side-channel protection. Only use Argon2i if you specifically need maximum side-channel resistance (e.g., key derivation in untrusted environments like browser JavaScript). Argon2d is rarely used for password hashing.

How long does Argon2 hashing take?

With OWASP-recommended settings (64 MB memory, 3 iterations, 4 threads), Argon2 takes 100-500ms on modern servers. Target 0.5-2 seconds per hash for good security-performance balance. Faster hashing = weaker security. Slower hashing = poor user experience. Adjust parameters based on your server's CPU/RAM and security requirements.

Can I convert bcrypt/PBKDF2 hashes to Argon2?

No—you cannot convert existing hashes because hashing is one-way. Instead, implement progressive migration: During user login, verify their password against the old hash (bcrypt/PBKDF2), then immediately generate a new Argon2 hash and update the database. Users who never log in keep their old hashes. This gradually migrates your database to Argon2 without forcing password resets.

Is this tool safe to use for production passwords?

This tool is for testing, development, and education only. All hashing happens in your browser (client-side) and nothing is stored or transmitted to our servers. However, for production applications, implement Argon2 directly in your backend code using established libraries. Never hash passwords in the browser or transmit plaintext passwords over the network—always hash server-side.

What is the PHC string format?

PHC (Password Hashing Competition) format is the standard encoding for password hashes. Example: $argon2id$v=19$m=65536,t=3,p=4$c2FsdA$hash. It includes the algorithm name, version, parameters, salt, and hash in a single string—everything needed for verification. This format is compatible with most password libraries and frameworks. Store the entire PHC string in your database's password field. PHC Format Specification.