File Checksum Calculator
Calculate a file’s SHA-256 or SHA-512 checksum and compare it with an expected value. Your file is read locally and is never uploaded by this tool.
Choose a file
Up to 100 MiB (104,857,600 bytes). Empty files are supported.
No file selected.
Choose a file to begin.
Checksum & comparison
Paste an expected checksum to compare.
Uppercase and lowercase hex are equivalent. Spaces around the value are ignored; spaces inside it, prefixes and checksum manifest lines are rejected.
Using File Checksum Calculator
Calculate a local file digest and compare it with a checksum supplied by its publisher. File contents stay in your browser.
- Select one file up to 100 MiB and choose SHA-256 or SHA-512. Load example creates a three-byte abc file with a known SHA-256 checksum.
- Click Calculate checksum. The indicator shows reading and hashing stages; Cancel stops processing.
- Paste the expected hexadecimal checksum, check Match or Mismatch, then copy the digest or download the JSON report.
Example
File bytes: abc (no newline) SHA-256: ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad
Questions & answers
Are my files uploaded or stored?
No. The file is read and hashed in a local browser worker. This tool does not upload or save file contents, filenames or digests. The optional report downloads to your device.
Which algorithms are supported?
SHA-256 and SHA-512 are supported. Their hexadecimal digests contain 64 and 128 characters respectively. Choose the same algorithm as the expected checksum.
Does a matching checksum prove a file is safe?
A match confirms that the calculated digest equals the expected value. It does not establish the publisher’s identity or prove the file is safe. Obtain the expected checksum from a trusted source.
What format should the expected checksum use?
Paste only the hexadecimal checksum. Uppercase and lowercase are equivalent, and surrounding whitespace is ignored. Internal spaces, prefixes such as sha256:, filenames and manifest lines are rejected.
Why can a text file produce a different checksum?
Hashing uses exact file bytes. A trailing newline, different line endings, character encoding or byte-order mark changes those bytes. The abc example contains exactly three bytes without a newline.
Does renaming a file change its checksum?
No. The filename is not part of the digest. Empty files are also valid and have a defined digest for each algorithm.
Why is there a file limit and no percentage progress?
This Web Crypto implementation requires the complete file in memory. Files are capped at 100 MiB and processing stops after 30 seconds. The browser digest API does not expose percentage progress, so the indicator shows reading and hashing stages.
Why does hashing require HTTPS?
Web Crypto is available in supported browsers in secure contexts such as HTTPS and localhost. Use HTTPS on the hosted website. If the worker or crypto API is unavailable, the page shows an error instead of producing a result.
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