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File Checksum Validator

Compare a published MD5, SHA-1, SHA-256, SHA-384, or SHA-512 checksum with the exact bytes of a local file.

Text limit: 1 KB · File limit: 100 MB · Processing timeout: 120 s
How can I verify this?

Open your browser DevTools and the Network panel, optionally clear existing requests, then run the tool. Page assets or consent-based analytics may still load, but tool payloads, files, keys, and results are not sent for processing.

Verify a file checksum

Paste the expected hex checksum and choose the local file. Auto detection uses only an unambiguous digest length.

Hex is accepted case-insensitively. Whitespace between byte groups is ignored; filenames and command output are not accepted.

No file selected

Choose the exact file whose checksum you want to verify.

Verification result

The match result, resolved algorithm, file size, and calculated checksum will appear here.

Exact file checksum comparison

DecodeLens calculates the selected digest from the file's exact bytes in a browser worker and compares normalized hex values. The expected checksum and file are not sent to a server.

Verification boundaries

  • Supports hexadecimal MD5, SHA-1, SHA-256, SHA-384, and SHA-512 checksums.
  • Auto mode infers the algorithm only from the unique standard hex length: 32, 40, 64, 96, or 128 characters.
  • Whitespace and hex letter case are normalized; checksum command output, filenames, labels, and non-hex encodings are rejected.
  • A matching checksum shows byte-level integrity against the supplied value. It does not prove who published that value or whether its source is trustworthy.
  • MD5 and SHA-1 are available for legacy compatibility and must not be treated as collision-resistant security checks.

Related tools for this workflow

Continue with tools that decode, convert, inspect, or verify the same data.

Verify a downloaded file

Copy the checksum published by the file provider, leave the algorithm on Auto when the hex length is standard, choose the downloaded file, and compare the calculated result.

Expected SHA-256

ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad

Result

MATCH · SHA-256 · 3 B

Checksum Validator FAQ

Does a matching checksum prove that a download is safe?

No. It proves only that the selected file bytes match the checksum you supplied. The checksum source can still be wrong or compromised.

How does automatic algorithm detection work?

It uses only standard hexadecimal digest length. DecodeLens does not guess from filenames, labels, or surrounding command output.

Why are MD5 and SHA-1 included?

Some legacy download pages still publish them. They are supported for compatibility, with a warning that they are not collision-resistant choices for new security workflows.

Is the selected file uploaded?

No. The file is read and hashed in this browser. It is not placed in the URL or persisted by the continuation flow.