Hash Generator Online
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes from any text instantly. All hashing runs in your browser using the Web Crypto API — your input is never sent to any server.
🔒 All hashing runs in your browser. Your text is never transmitted to any server.
When to use each algorithm
| Algorithm | Output size | Speed | Use case | Security |
|---|---|---|---|---|
| MD5 | 128 bit / 32 hex | Very fast | Checksums, file integrity | Broken (collisions) |
| SHA-1 | 160 bit / 40 hex | Fast | Legacy systems, Git | Deprecated |
| SHA-256 | 256 bit / 64 hex | Fast | Digital signatures, certificates | Secure |
| SHA-512 | 512 bit / 128 hex | Fast | High-security applications | Secure |
What is a hash function?
A cryptographic hash function takes any input (text, file, password) and produces a fixed-length string called a digest. Hash functions have three key properties:
- Deterministic — the same input always produces the same hash.
- One-way — you cannot reverse a hash to recover the original input.
- Avalanche effect — a tiny change to the input produces a completely different hash.
MD5 vs SHA-256 — which should you use?
Use SHA-256 for any security-critical purpose: verifying file downloads, digital signatures, or data integrity in production systems. MD5 is only appropriate for non-security uses like quick checksums in internal tools where collision resistance is not required.
For password storage, never use MD5 or SHA-256 directly — use bcrypt, scrypt, or Argon2, which are purpose-built for password hashing and include salting and deliberate slowness.
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Frequently Asked Questions
A hash (or digest) is a fixed-length string produced by a hash function from any input. The same input always produces the same hash, but even a tiny change to the input produces a completely different hash. Hashes are one-way — you cannot reverse a hash to recover the original input.
MD5 produces a 128-bit (32 hex character) hash. It is fast but cryptographically broken — collisions can be generated deliberately. SHA-256 is part of the SHA-2 family, producing a 256-bit (64 hex character) hash, and is considered cryptographically secure for most applications.
MD5 is not safe for security-critical uses such as password hashing or digital signatures. It is still acceptable for non-security purposes like checksums to detect accidental data corruption. For passwords, use bcrypt, scrypt, or Argon2 — not MD5 or SHA-256.
No. All hashing is performed entirely in your browser using the Web Crypto API (SHA algorithms) and a pure-JavaScript MD5 implementation. Your input text never leaves your device.
Not directly. SHA-256 is a one-way function — there is no mathematical way to derive the input from the hash. However, short or common inputs can be looked up in precomputed rainbow tables. This is why password hashing should always use a salt and a purpose-built algorithm like bcrypt.