Hashing text and verifying file checksums
A cryptographic hash is a fixed-length fingerprint of data: change one byte and the digest changes completely. This tool computes SHA-256, SHA-512 and SHA-1 with the browser's native Web Crypto API (hardware-accelerated) and MD5 with a compact local implementation — for text, live on every keystroke; for files, via drag & drop up to 200 MB. Your data never leaves the device.
The most common use: verifying downloads. Publishers list a checksum (usually SHA-256) beside each file; hash your downloaded copy here and paste the published value into the verify box — matching is done algorithm-aware and case-insensitively. A mismatch means corruption or tampering: delete the file. For authenticity use SHA-256/512 only; SHA-1 and MD5 are collision-broken and included solely for matching legacy checksums.
One caution: plain hashes are the wrong tool for storing passwords — brute force is too fast. Password systems need slow, salted algorithms (bcrypt, scrypt, Argon2). Need a strong password instead? Use the Password Generator; encoding data rather than hashing? See Base64 Encoder/Decoder.