File checksum verifier
Check a download against its published checksum. Works on files of any size.
How to use it
- Add the file you downloaded. Large files are fine; they are read in pieces.
- Paste the checksum from the download page into the second box, or leave it empty to just calculate.
- Press the button. “MATCH” means the file is exactly the one that was published.
Questions
What does a matching checksum tell me?
That every byte of your file is identical to the file the checksum was made from, so the download is not damaged or cut short. It only protects against tampering if you got the checksum from a trusted place, such as the official site over HTTPS, and not from the same page or mirror as the file.
Which type should I pick?
Use the type the download page lists. If you paste the checksum, the type is chosen from its length: 64 characters is SHA-256, 40 is SHA-1, 32 is MD5, 128 is SHA-512. Prefer SHA-256 or SHA-512; MD5 and SHA-1 can be forged by someone who plans for it and are only fine for catching accidental damage.
Can it read a SHA256SUMS file?
Yes. Paste the whole contents. Each line is matched to your files by name, so you can add several files at once. Lines for files you did not add are ignored.
How big a file can I check?
There is no fixed limit: the file is read in 8 MB pieces and never loaded whole. A 6 GB disk image takes about a minute or two, depending on your device and the type. Keep the page open while it works.
What is the list file it gives me?
The same checksums in the format of sha256sum, md5sum and similar tools: the checksum, two spaces, the file name. You can check files later on a computer with “sha256sum -c SHA256SUMS.txt”.
Are my files uploaded anywhere?
No. This tool runs in your browser, so your files stay on your device and are never sent to a server.
Is it free?
Yes, you can use it for free. A subscription removes limits and unlocks premium tools.