Hash calculator
MD5, SHA-1, SHA-2, SHA-3, RIPEMD-160 and CRC32 for text, hex or files, with HMAC and verify.
Runs on your device · nothing is uploaded
Algorithms
With a key, results are HMACs (RFC 2104).
| Algorithm | Size | Hash value | Copy |
|---|
What is a hash?
A hash function turns any input (a word, a document, a 4 GB ISO file) into a short, fixed-length fingerprint. Change a single bit of the input and the fingerprint changes completely. You can't turn a hash back into the original data, which is why hashes are used to check downloads, detect tampering, and store passwords safely (with special slow algorithms).
Which algorithm should I use?
| Algorithm | Use it for | Security |
|---|---|---|
| SHA-256, SHA-512 | File and download checks, digital signatures, certificates | Strong. The everyday choice. |
| SHA3-256, SHA3-512 | Modern designs that want a different construction to SHA-2 | Strong |
| MD5, SHA-1 | Matching old checksums and legacy systems only | Broken: collisions can be created on purpose |
| CRC32, Adler-32, FNV-1a | Catching accidental errors (ZIP files, network frames, hash tables) | Not security hashes at all |
How to verify a download
- Copy the checksum published on the official download page (often SHA-256).
- Open the File tab above, choose the file you downloaded, and paste the published value into Verify.
- A green match means the file is exactly what the publisher released. No match means a corrupted or changed file, so download it again from the official site.
You can also check from the command line:
# Windows (PowerShell or Command Prompt)
certutil -hashfile installer.iso SHA256
# macOS
shasum -a 256 installer.iso
# Linux
sha256sum installer.isoWhat is HMAC?
An HMAC mixes a secret key into the hash. Only someone who knows the key can produce the same value, so it proves a message wasn't changed and came from someone holding the key. APIs and webhooks often sign requests with HMAC-SHA256.
Passwords: never store passwords with a plain fast hash like MD5 or SHA-256. Use a slow, salted password-hashing algorithm such as Argon2, bcrypt or scrypt.