SHA-256 File Hash Checker

How it works

Select a file, then calculate its digest. The browser reads the file into an ArrayBuffer and passes those bytes to the Web Crypto SHA-256 implementation. The result is displayed as 64 lowercase hexadecimal characters. Renaming the file does not change its digest, because its name is not included. Changing even one byte normally produces a very different digest.

For a useful integrity comparison, obtain the expected hash through a trusted channel, such as the software publisher’s HTTPS download page. A matching hash says the computed digest matches that reference; it does not establish who created the file, whether the reference was authentic, or whether the software contains malware. Digital signatures and trusted distribution practices serve different purposes.

The maximum file size is 100,000,000 bytes. This is a deliberate memory limit because this implementation reads the entire file at once. Browser memory use can exceed the file size, and low-memory devices may still fail below the limit. For large files, use a trusted streaming command-line utility. Web Crypto requires an appropriate secure browser context; the tool reports when it is unavailable instead of substituting an insecure or invented result. This tool does not upload your file.

A worked example

An empty file has SHA-256 e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855. This known value is useful for checking the calculation with a zero-byte test file.

Common questions