How this hash generator works
A hash function turns any input — a single word or an entire document — into a fixed-length string of characters known as a hash or digest. The same input always produces the same digest, yet changing even one character produces a completely different result. That property makes hashes ideal for verifying that data has not been altered.
This tool reads the text you type, encodes it as UTF-8 bytes, and feeds those bytes to the browser's built-in Web Crypto API (crypto.subtle.digest) for the SHA-1, SHA-256, SHA-384 and SHA-512 algorithms. The raw output is a block of bytes, which we convert to a lowercase hexadecimal string. Because all of this runs locally, your text is never sent anywhere.
hello is 2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824 — a 64-character hex string. Type hello in the box above and you will see exactly that value.| Algorithm | Output size | Hex characters | Status |
|---|---|---|---|
| SHA-1 | 160-bit | 40 | Legacy — broken, avoid for security |
| SHA-256 | 256-bit | 64 | Recommended |
| SHA-384 | 384-bit | 96 | Secure |
| SHA-512 | 512-bit | 128 | Secure |
Reference note: hashing uses the UTF-8 encoding of your text and runs in a secure (HTTPS) context, which the Web Crypto API requires. MD5 is intentionally absent — it is insecure and the browser API does not expose it.
Frequently asked questions
- What is a hash function?
- A hash function takes any input — a word, a file, a whole book — and produces a fixed-length string called a hash or digest. The same input always gives the same output, but even a one-character change produces a completely different result.
- What is SHA-256 used for?
- SHA-256 verifies file integrity, fingerprints passwords, signs software and secures blockchains such as Bitcoin. Its 256-bit output makes collisions effectively impossible with current technology.
- Is a hash reversible?
- No — a cryptographic hash is one-way. You cannot recover the original text from the hash; the only way to match a hash is to try candidate inputs and hash each one.
- What's the difference between SHA-1 and SHA-256?
- SHA-1 produces a 160-bit (40 hex) digest and is now broken — practical collisions exist. SHA-256 produces a 256-bit (64 hex) digest and remains secure, so it is the recommended choice.
- Why is MD5 not here?
- MD5 is cryptographically insecure, and the browser's Web Crypto API does not provide it at all. Since this tool relies on that native API, MD5 is simply unavailable — which is just as well.
- Are my inputs sent to a server?
- No. All hashing happens locally in your browser. Your text never leaves your device and is never uploaded, logged or stored.