SHA-256 / MD5 Hash Generator
Generate MD5, SHA-1, SHA-256, and SHA-512 cryptographic hashes of any text.
Useful for data integrity verification, checksums, and security analysis.
Cryptographic Hash Functions
A cryptographic hash function takes any input and produces a fixed-length output (the hash or digest). The same input always produces the same output, but even a tiny change in input produces a completely different hash.
The four hash algorithms shown:
| Algorithm | Output Length | Security Status |
|---|---|---|
| MD5 | 128-bit (32 hex chars) | Cryptographically broken — use only for checksums |
| SHA-1 | 160-bit (40 hex chars) | Deprecated — avoid for security |
| SHA-256 | 256-bit (64 hex chars) | Secure — widely used today |
| SHA-512 | 512-bit (128 hex chars) | Secure — strongest option |
What makes a good hash function?
- Deterministic: same input → same output, always
- One-way: computing the input from the hash is computationally infeasible
- Avalanche effect: changing one bit of input changes ~50% of output bits
- Collision resistance: very hard to find two inputs with the same hash
Common uses:
- File integrity checking: compare hash before and after download
- Password storage: store the hash, not the password (use bcrypt/argon2 for passwords, not MD5/SHA)
- Digital signatures and certificates
- Git commit identifiers (SHA-1 / SHA-256)
- Blockchain transaction hashing (SHA-256)
- API request signing (HMAC-SHA256)
Why is MD5 broken? MD5 collisions (two different inputs with the same hash) can be computed in seconds on modern hardware. This makes MD5 unsuitable for security applications but still useful for non-security checksums (file downloads, data deduplication).
SHA-256 in practice: Bitcoin uses double-SHA-256 (SHA-256 applied twice) for block hashing. TLS 1.3 and modern HTTPS certificates rely on SHA-256.