File Checksum Calculator
Upload a file to instantly calculate its checksum and verify it matches what you expect.
Choose a file to calculate its checksum.
Your files are processed locally in your browser. They are not uploaded to our servers.
How to use
- Choose a file from your device.
- Pick a hash algorithm.
- Compare the resulting checksum against the one you were given.
What is this tool?
File Checksum Calculator reads a file's raw bytes and computes a cryptographic checksum using your browser's built-in Web Crypto engine — the same technique used to verify that a downloaded file hasn't been corrupted or tampered with. Unlike a text hash tool, this works directly on the file itself, not on typed text.
Common uses
- Verifying a downloaded file matches the checksum published by its source
- Confirming two copies of a file are byte-for-byte identical
- Checking a file wasn't corrupted during a transfer
- Generating a checksum to publish alongside a file you're distributing
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FAQ
Which algorithm should I use?
SHA-256 is the most common choice today; use whichever algorithm the checksum you're comparing against was generated with.
Does file size affect how long this takes?
Very large files may take a moment longer since the entire file is read and hashed in your browser.
Is my file uploaded to a server?
No, the file is read and hashed entirely in your browser using the Web Crypto API — it never leaves your device.