File Checksum Verifier

A free, open-source, client-side tool to compute a file's SHA-256, SHA-384, SHA-512, and BLAKE2b checksums and compare them to a published hash. Use it to verify downloads like Tor Browser, Tails, or the Monero GUI. The file never leaves your device.

Drag a file here, or choose a file.

FAQs

What is this site?

This tool computes the cryptographic checksum (hash) of a file you choose, so you can compare it to the hash a project publishes and confirm your download was not corrupted or tampered with. It supports SHA-256, SHA-384, SHA-512, and BLAKE2b-512.

Does my file get uploaded anywhere?

No. The file is read and hashed entirely in your browser using the WebCrypto API and a self-hosted BLAKE2b implementation. Nothing is sent to any server, so you can disconnect from the internet and it still works.

How do I verify a download?

Find the official checksum on the project's website (for example a sha256sum value or a hashes.txt file), select your downloaded file here, then paste the published hash into the compare box. A green match means the files are byte-for-byte identical. For full assurance, also check the project's GPG signature on the checksum file.

Why is BLAKE2b slower than SHA?

The SHA functions run on the browser's built-in, hardware-accelerated WebCrypto. BLAKE2b runs in JavaScript, so very large files take longer. It is processed in chunks so the page stays responsive. On load, the BLAKE2b code runs a known-answer self-test and disables itself if it does not reproduce the expected vector, so it can never show you a wrong hash.

Can I link to a prefilled comparison?

Yes. Add ?expected=... to the URL to prefill the published hash. You still choose the file to hash, and the comparison runs once the checksum is computed.

Is this site open source?

Yes! You can find the full source code on GitHub.

Disclaimer: This tool is provided "as is" with no warranties. A matching checksum confirms integrity, not authenticity. Verify the publisher's signature for full assurance.