What is a Hash?
A cryptographic hash is a one-way function that converts input of any size into a fixed-length string of characters. The same input always produces the same hash, but you cannot reverse the hash back to the original input.
Our Hash Generator supports multiple algorithms including SHA-1, SHA-256, SHA-384, and SHA-512. All hashing is done securely in your browser using the Web Crypto API.
Hash Algorithms Compared
| Algorithm | Output Length | Security Status |
|---|---|---|
| MD5 | 128 bits (32 hex) | Broken - don't use |
| SHA-1 | 160 bits (40 hex) | Deprecated - avoid |
| SHA-256 | 256 bits (64 hex) | Secure - recommended |
| SHA-384 | 384 bits (96 hex) | Secure |
| SHA-512 | 512 bits (128 hex) | Secure |
⚠️ Don't Hash Passwords Directly
For password storage, use specialized algorithms like bcrypt, scrypt, or Argon2. Simple SHA hashes are vulnerable to rainbow table attacks.
Common Use Cases
File Integrity
Hash a file before and after transfer. If the hashes match, the file wasn't corrupted or tampered with. This is how package managers verify downloads.
Unique Identifiers
Hash content to create unique IDs (content-addressable storage). Git uses SHA-1 hashes to identify commits and files.
Data Verification
Store a hash of sensitive data to verify it later without storing the actual data. Useful for checking if a password matches without reversing encryption.
Hash Properties
- Deterministic: Same input always gives same output
- One-way: Cannot reverse the hash to get the input
- Collision-resistant: Hard to find two inputs with the same hash
- Avalanche effect: Tiny input changes produce completely different hashes
Frequently Asked Questions
Which algorithm should I use?
For most purposes, SHA-256 is the best choice. It's secure, widely supported, and the industry standard. Use SHA-512 only if you need extra security margin.
Can I decrypt a hash?
No! Hashing is one-way by design. You can only compare hashes or use rainbow tables (pre-computed hashes) to find common inputs—which is why you should always use salt for passwords.
Why is my hash different from other tools?
Encoding matters! Make sure both tools use the same text encoding (usually UTF-8). Trailing whitespace or different line endings can also produce different hashes.