File Checksum
Compute a file's SHA-256, SHA-512 and SHA-1, and check it against the checksum somebody published.
Free No signup Runs in your browser — nothing uploaded
What it does
File Checksum reads the whole document before doing anything, so what comes back is either valid output or a specific error with the position that caused it — not a partially rewritten file.
When you need it
Usually when something has already gone wrong: a config file an application will not load, an API response that has to be read by a human, or an export that has to be checked before it goes anywhere near a database.
Limits and caveats
Key order is preserved as it appears in the input. Very large documents are limited by your device's memory rather than by an upload cap, since the parsing happens locally. Everything happens in your browser, so the file never leaves your device.
How to file checksum
- Drop the file.
- Paste the checksum you were given.
- It says match or no match.
Frequently asked questions
- What is this actually for?
- Two things. Proving a download was not corrupted, and proving it was not swapped for something else. A project publishes the SHA-256 of its installer; if yours differs, you did not get their file.
- Why paste the checksum instead of reading both?
- Because comparing two 64-character hex strings by eye is exactly the task people are worst at, and 'close enough' is the failure this is meant to prevent. The machine compares them and the answer is one word.
- Why is SHA-1 marked as unfit?
- Because it is broken for proving a file was not tampered with — two different files can be made to share a SHA-1. It is still here because checksums published years ago are SHA-1, and it remains fine for noticing a truncated download.
- Do my files get uploaded?
- No. This tool runs entirely in your browser, so the file never leaves your device.