What hashes are for
A hash is a one-way fingerprint: the same input always yields the same fixed-length output, but you can't work backwards from the hash to the text. They're used to verify downloads (compare the published checksum), detect changes in files, and as building blocks in security.
Which algorithm should I use?
| Algorithm | Length | Use for |
|---|---|---|
| MD5 | 128-bit | Checksums only — not secure |
| SHA-1 | 160-bit | Legacy — avoid for security |
| SHA-256 | 256-bit | The modern default |
| SHA-384 / SHA-512 | 384 / 512-bit | Extra-strength integrity |
Private by design. SHA hashes use the browser's Web Crypto API and MD5 runs locally in JavaScript — your text never leaves your device.
Frequently asked questions
What is a hash?
A fixed-length fingerprint of data. Same input → same hash, but it can't be reversed. Used for integrity checks and checksums.
Is MD5 secure?
No — MD5 and SHA-1 are broken for security (collisions). Use SHA-256 or stronger for anything sensitive.
Is my text uploaded?
No — SHA uses the browser's Web Crypto and MD5 runs locally. Nothing is sent anywhere.
More free tools
Security: Password Generator · Text: Case Converter · See all Alienated Tools.