How to use the Hash Generator tool
- Type or paste text, or choose a file (up to 1 GB).
- Optionally enter an HMAC key or a hash to compare with.
- Copy the hash you need in hex or Base64.
What a hash is for
A cryptographic hash turns any input into a short fixed-size fingerprint. Change a single bit of the input and the hash changes completely. That makes hashes ideal for checking that a file was not corrupted or tampered with: software publishers list the SHA-256 of each download, and you compare it with the hash of the file you received.
Which algorithm to use
- SHA-256: the default choice for checksums, signatures and integrity checks.
- SHA-512 / SHA-384: same family, longer output, and often faster on 64-bit CPUs.
- SHA-1: broken for security since practical collisions were shown in 2017. Still seen in Git and old systems.
- MD5: broken for security. Fine only for spotting accidental corruption or deduplicating files.
- CRC32: not a cryptographic hash. Detects transmission errors in ZIP files, Ethernet and PNG.
One important warning from security work: none of these should be used to store passwords. They are designed to be fast, which lets attackers try billions of guesses per second. Use bcrypt, scrypt or Argon2 for passwords; our htpasswd generator creates bcrypt hashes.
HMAC
With a key, the tool computes an HMAC, which proves that the data was produced by someone who knows the key. Webhooks from Stripe, GitHub and many APIs are signed this way, so this is a quick way to debug a signature mismatch: compute the HMAC of the exact request body and compare.
Privacy
Text and files are hashed in your browser with the Web Crypto API. Nothing is uploaded.
Frequently asked questions
Can a hash be reversed to get the original text?
No. But short or common inputs can be found with precomputed tables, which is why unsalted MD5 or SHA hashes of passwords are unsafe.
Why does my hash differ from another tool?
Usually invisible differences in the input: a trailing newline, Windows line endings (CRLF) or a different text encoding. This tool hashes text as UTF-8.
How do I check the hash of a file on my computer?
Linux and macOS: sha256sum file or shasum -a 256 file. Windows: Get-FileHash file -Algorithm SHA256 in PowerShell.
Is there a file size limit?
Up to 1 GB, limited by browser memory.