Cryptographic Hash Generator
Generate secure cryptographic hashes using industry-standard algorithms including MD5, SHA-1, SHA-256, and SHA-512. Our free hash generator runs entirely in your browser, ensuring your data never leaves your device.
What is a Cryptographic Hash?
A cryptographic hash function takes an input (or message) and returns a fixed-size string of bytes. The output is unique to the input - even a tiny change in the input produces a completely different hash. This property makes hashes perfect for verifying data integrity and storing passwords securely.
Hash Algorithm Comparison
- MD5 (128-bit): Fast but cryptographically broken. Use only for non-security purposes like checksums or cache keys. Not recommended for passwords or signatures.
- SHA-1 (160-bit): Deprecated for security applications due to collision attacks. Avoid for new projects. Still used in Git for historical reasons.
- SHA-256 (256-bit): Industry standard for security applications. Part of the SHA-2 family. Excellent balance of security and performance. Recommended for most use cases.
- SHA-512 (512-bit): Maximum security from the SHA-2 family. Slower than SHA-256 but provides stronger security guarantees. Ideal for highly sensitive applications.
Common Uses for Hash Functions
- Password Storage: Hash passwords before storing in databases (with salt!)
- File Integrity: Verify downloads haven't been corrupted or tampered with
- Digital Signatures: Create unique fingerprints of documents or code
- Blockchain: Secure transaction data in cryptocurrencies
- Deduplication: Identify duplicate files or content
- Cache Keys: Generate unique identifiers for cached data
Hash Function Properties
A good cryptographic hash function must have these properties:
- Deterministic: Same input always produces same hash
- Fast: Quick to compute the hash for any input
- One-way: Impossible to reverse the hash to get the original input
- Avalanche Effect: Small change in input creates completely different hash
- Collision Resistant: Extremely difficult to find two inputs with the same hash
Security Best Practices
- Use SHA-256 or SHA-512 for security-critical applications
- Always add salt when hashing passwords (unique salt per password)
- Consider using specialized password hashing algorithms like bcrypt, Argon2, or PBKDF2
- Never use MD5 or SHA-1 for passwords or digital signatures
- Verify file hashes after downloading software or updates
When Not to Use Hashing
Hashing is not encryption. You cannot recover the original data from a hash. If you need to decrypt data later, use encryption algorithms like AES instead. Hashing is for one-way data transformation only.