About MD5

MD5 dates to 1992 and produces a 128-bit digest. Collisions can be manufactured cheaply, so it's unsuitable for anything security-related — but it remains everywhere as a fast checksum for downloads, cache keys, and deduplication.

Digests here are computed with the browser's WebCrypto API (MD5 runs locally in JavaScript, since WebCrypto dropped it). A hash is one-way: the same input always produces the same 128-bit digest, but the digest can't be reversed back into the input. Text you enter never leaves the page.