What is the best algorithm for password hashing?

Argon2id is currently the best choice for password hashing, followed by bcrypt. Both include built-in salting and are designed to be slow, making brute-force attacks difficult.

Can you reverse a hash to get the original password?

No, hash functions are one-way operations. You cannot mathematically reverse a hash to obtain the original password. Verification works by hashing the input again and comparing results.

Why is MD5 considered insecure for passwords?

MD5 is cryptographically broken - it's vulnerable to collision attacks and is too fast, making it easy to brute-force. Modern GPUs can compute billions of MD5 hashes per second.

What is bcrypt cost factor?

The bcrypt cost factor (4-15) determines how computationally expensive the hash is to compute. Higher values mean stronger security but slower hashing. A cost of 12 is recommended for most applications.

Password Hash Generator - Create Secure MD5, SHA256, bcrypt, Argon2 Hashes

Password to Hash

Hash Algorithm

bcrypt Cost Factor 12

4 (Fast) 15 (Secure)

Hash Functions Are One-Way

You cannot reverse a hash to find the original password. Hash functions are designed to be irreversible. The "Verify Hash" feature works by hashing your password again and comparing the results - not by reversing the hash.

Hash Algorithm Guide

Argon2id / bcrypt Best for Passwords

Modern password hashing algorithms with built-in salt. Argon2id is the PHC winner, while bcrypt is industry-proven. Both are resistant to rainbow table and brute-force attacks.

SHA-256 / SHA-512 Good for General Use

Secure cryptographic hash functions from the SHA-2 family. Fast and widely supported. Requires additional salting when used for password storage.

MD5 / SHA-1 Legacy Only

Cryptographically broken algorithms. Only use for compatibility with legacy systems. Vulnerable to collision attacks - never use for security purposes.