# Hash and HMAC generator

Calculate MD5, SHA-1, SHA-2, SHA-3, BLAKE2, BLAKE3 and CRC-32 hashes of text or a file, with optional HMAC.

https://codeknife.dev/en/hash-generator/

## What it does

Calculate MD5, SHA-1, SHA-2, SHA-3, BLAKE2, BLAKE3 and CRC-32 hashes of text or a whole file, with optional HMAC. Files are read in small slices, so large ones work too. Hashing happens in your browser, this page shows no ads, and links you share never contain your text or key.

## How to use it

1. Type or paste text, or drop a file onto the input.
2. Choose the algorithm and how the result is written: hex, uppercase hex, Base64 or URL-safe Base64.
3. To make an HMAC, turn it on and enter a key. The key is read as UTF-8 text.
4. Copy the hash. Turn on the per-line option to hash each line separately.

## Examples

SHA-256 of `hello`:

```
2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824
```

CRC-32 of `123456789`:

```
cbf43926
```

## Good to know

- SHA-256 is a safe default. MD5 and SHA-1 are broken for security and are only useful to match old checksums.
- CRC-32 is a checksum, not a hash function, so it cannot be used with HMAC.
- Plain hashes are far too fast to protect passwords. Use Argon2, scrypt or bcrypt for that.

## What is a hash?

A hash function turns any input into a short, fixed-size fingerprint. The same input always gives the same hash, and a different input gives a different one. Hashes are used to verify downloads, detect changes and index data. HMAC mixes a secret key into the hash so only someone with the key can produce or check it.

## Frequently asked questions

### Which algorithm should I use?

SHA-256 is a safe default. SHA-3 and BLAKE3 are modern alternatives. MD5 and SHA-1 are broken for security, so use them only to match old checksums. CRC-32 only catches accidental corruption.

### Can I hash a password with this?

Not for storing it. Plain hashes are far too fast to guard passwords; use a dedicated password hash such as Argon2, scrypt or bcrypt on your server.

### Is my text or file uploaded?

No. Hashing runs in your browser, and files are read in small pieces so large ones work too. What you type is never sent to our servers, and this page shows no ads.