File Hash (Checksum)

You downloaded an Ubuntu ISO or an installer and the site lists the expected SHA-256. How do you verify it without installing anything or opening a terminal? Drag the file onto this page and it computes MD5, SHA-1, SHA-256, SHA-384 and SHA-512 in one pass. If the computed hash matches the published one, the file arrived intact; if even a single byte changed along the way, the hash comes out completely different. You can also paste text and get the same five digests.

Hashes have an avalanche effect: flip one bit in the file and the entire result changes, so there is no such thing as an 'almost matching' hash. MD5 and SHA-1 are included because older documentation still publishes them, but both have known collisions: they detect accidental corruption, not deliberate tampering. On the text tab, the digest is computed over the exact UTF-8 bytes, which means a trailing newline or CRLF instead of LF already produces a different result.

To verify a download, copy the hash published on the official site and compare it against the SHA-256 shown here; checking the first and last characters is not enough, compare the whole string or use Ctrl+F with the copied value. The file is read by FileReader and processed locally with no upload, which is why the page keeps working offline once loaded. The practical limit is memory: the entire file goes into the tab's RAM, so multi-gigabyte files may choke; for those, use shasum or certutil in a terminal.