md5sum — compute an MD5 checksum
SYNOPSIS
md5sum <text...>
DESCRIPTION
Computes the MD5 checksum of the given text (UTF-8 encoded) and prints it as lowercase hex, followed by " -" (as for standard input). The Web Crypto API has no MD5, so it is computed in JavaScript.
MD5 is broken for security use (collisions are cheap) — it lives here as a checksum and as a companion to hashcat.
HOW IT WORKS
MD5 turns any input into a fixed 128-bit fingerprint, shown as 32 hexadecimal characters. The same text always gives the same hash, and the smallest change gives a completely different one. The algorithm is implemented in the page itself, and the text is hashed as UTF-8 bytes, so the result matches echo -n "text" | md5sum on Linux.
USE CASES
- verify a download against a published MD5 checksum;
- detect accidental changes or duplicates in data;
- produce test vectors for the hashcat command.
SECURITY
Do not use MD5 for passwords or signatures: collisions can be forged cheaply. Prefer SHA-256 (sha256sum) for anything security-related.
EXAMPLES
md5sum hello md5sum The quick brown fox