About the Checksum Calculator
Download pages rarely agree on which digest to publish. One project lists SHA-256, another still shows MD5, and mirrors sometimes print SHA-1. Rather than guessing and running the wrong algorithm, this page computes a whole set at once and prints them together with the file name and size, so whichever value the publisher chose is already on screen.
Paste the published string into the Expected value box and the result gains a verdict line. Any spacing, colons or case differences are normalised before comparison, so a value copied out of a table with stray whitespace still matches. When a digest agrees the page names which algorithm matched, which is itself useful information when the download page forgot to say. When nothing matches you get a plain statement rather than an ambiguous silence.
The file is read with the browser FileReader and hashed by a WebAssembly implementation, so the bytes never leave the machine. That matters for private archives and for large installers where uploading would be slower than the check itself. Pick the Algorithms set to trade speed against coverage: MD5 only is fastest, while the modern set adds SHA3-256 and BLAKE3 for newer projects. To compare two strings you already have, use Checksum Compare, and for a digest of pasted text rather than a file try All Hash Generator.
How to use
- Drop the downloaded file on the left pane or click it to browse.
- Choose an Algorithms set, or leave the common three selected.
- Paste the published checksum into Expected value to get a verdict line.
- Read the match line, or compare the digests by eye if you prefer.
Common questions
- Does the file get uploaded anywhere?
- No. It is read straight from disk by the browser and hashed locally, so it never crosses the network.
- Which algorithm should I compare?
- Use whichever one the download page published. If it offers a choice, prefer SHA-256 over MD5 or SHA-1.
- My checksum has colons and spaces in it. Will it still match?
- Yes. Non hex characters are stripped and case is ignored before the comparison runs.
- Why is MD5 still offered if it is broken?
- MD5 is unsafe against a deliberate attacker but is still fine for spotting an accidentally corrupted download, and many older projects publish nothing else.