Compute a local file’s SHA-256 and optionally compare a known digest without uploading the file.
Your input
Outputs are cleared when the input changes.
Result
Enter your data or use the example, then run the tool.
Worked example
The built-in sample contains the exact bytes abc and hashes to ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad.
An empty file hashes to e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855.
Method
Read the file into an ArrayBuffer and call SubtleCrypto.digest with SHA-256, displaying 64 lowercase hexadecimal digits.
Normalize and validate an optional expected hash, then compare all 64 characters. File names are not part of the digest.
Limits
One file up to 100 MiB, fully held in memory. Requires secure-context Web Crypto.
Cancellation stops waiting; native file reads and digest work cannot be forcibly stopped by the standard API. No encryption, malware scan or file opening.
Your inputs stay on this device. Only optional, consented page visits are measured. Input values, files, filenames and processing logs are not sent to Analytics.
When switching languages, text, settings and selected files are temporarily kept on this device. Transfers are removed after restoring; interrupted transfers are cleaned up on a later visit. Inputs and files are never uploaded.