Calculate cryptographic hashes for text or file verification. Essential for verifying file integrity, checking downloads, and security analysis.

Calculate Hash

Common Use Cases

  • File Verification: Verify downloaded files match published checksums
  • Integrity Checking: Ensure files haven’t been modified or corrupted
  • Password Storage: Understand how passwords are hashed (DO NOT use MD5/SHA-1 for passwords)
  • Digital Signatures: Verify document integrity
  • Change Detection: Detect if configuration files have changed
  • Software Distribution: Verify package integrity before installation

Security Notes

Hash Strength (from weakest to strongest):

  1. MD5 (128-bit)

    • ⚠️ BROKEN - Do not use for security
    • Vulnerable to collision attacks
    • Only use for non-security checksums

  2. SHA-1 (160-bit)

    • ⚠️ DEPRECATED - Do not use for security
    • Vulnerable to collision attacks since 2017
    • Being phased out across industry

  3. SHA-256 (256-bit)

    • ✓ SECURE - Current industry standard
    • Part of SHA-2 family
    • Use for file verification and integrity checks

  4. SHA-512 (512-bit)

    • ✓ SECURE - Strongest option
    • Part of SHA-2 family
    • Better for high-security requirements

Examples

Verifying ISO Downloads:

Lang: 
Downloaded: ubuntu-24.04-desktop-amd64.iso
Published SHA-256: a435...b2c9
Calculated SHA-256: a435...b2c9
✓ Hashes match - file is authentic

Important Notes

  • Hashes are one-way functions - you cannot reverse them to get the original text
  • Even a single character change produces a completely different hash
  • Same input always produces the same hash (deterministic)
  • Different inputs can theoretically produce the same hash (collision), but this is extremely rare with SHA-256/512
  • For password hashing, use bcrypt, scrypt, or Argon2 (not these hashes)