A hash turns any input into a fixed-length fingerprint. The same input always produces the same hash, and even a tiny change produces a completely different one. That makes hashes ideal for checking that data has not changed. Here is how to generate them and which algorithm to pick.
What a hash is for
Hashes are one-way: you cannot turn a hash back into the original data. Common uses include:
- Integrity checks: confirm a downloaded file matches the published checksum.
- Change detection: see whether two pieces of text or two files are identical.
- Deduplication and caching keys: a short, stable identifier for content.
A hash is not encryption, and on its own it is not how you should store passwords (that needs a slow, salted algorithm like bcrypt).
MD5 vs SHA-1 vs SHA-256
- MD5: fast and short, but broken for security. Fine for non-security checksums, never for anything an attacker could target.
- SHA-1: also considered weak now. Avoid for new work.
- SHA-256: the current default. Strong, widely supported, and the right choice when integrity matters.
For a simple “did this change?” check, MD5 is fine. For anything security-related, use SHA-256.
Generate a hash in two steps
- Open the Hash Generator and paste your text.
- Read off the MD5, SHA-1, SHA-256, and SHA-512 values, and copy the one you need.
It runs entirely in your browser using the native crypto API, so your input stays on your device.
Related tools
- Hashing a password specifically? Use the Bcrypt Generator.
- Need random secrets instead? Try the Password Generator.
- Encoding data for transport? See Base64 Encode / Decode.
Pick SHA-256 unless you have a reason not to, paste your text, and copy the fingerprint.