File Hash Checker
Reads the file locally and computes SHA-256. Paste a published checksum to compare.
SHA-256
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Comparison
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File
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Worked example
A checksum verifies that a download completed without corruption or tampering. It only proves anything if the published hash came from a source you trust independently of the file itself.
Verifying a download means comparing the hash you compute against the hash the publisher listed. Both halves matter: computing the hash is easy, knowing which hash to trust is the actual security question.
Why the file never uploads
The file is read through a data URL and hashed with WebCrypto in the tab. For a 1 GB file this will be slow and memory-hungry — a command-line tool is the right instrument past a few hundred megabytes.