Archive Integrity Pre-Check
Know whether an archive is worth extracting — before the extractor throws a CRC error.
Archive Integrity Pre-Check
Catch a truncated or half-overwritten ZIP/RAR before you waste time extracting it. Checks the container structure locally.
Report
The integrity report appears here.
When to use this
Run it on any archive that errors on open, that came from a flaky connection, or that a colleague insists “works on my machine.” A truncated download is the single most common cause of “cannot open ZIP file” and “CRC error”, and this tool spots the tell-tale missing end-of-directory record in seconds.
Worked example
A 4 MB data.zip fails to extract with “central directory not found.” You drop it in: the PK header is present but the end-of-directory record is missing, so the tool tells you the file is truncated. You re-download — this time the record is found and extraction succeeds. No more guessing.
What it can and can’t verify
For ZIP it checks the container is complete (header + end-of-directory). It does not recompute every entry’s CRC — that is the extractor’s job — but a complete container means the data is almost certainly intact. For RAR/GZ/7-Zip it confirms the file starts with the right signature; deep CRC verification needs a desktop tool. It never repairs; it only diagnoses.
FAQ
“CRC error” vs “truncated” — what’s the difference? A CRC error means an entry’s checksum failed (bytes changed). Truncation means the file simply ends early. Both usually mean re-download, but truncation is what this tool can confirm structurally.
It says complete but extraction still fails. Then an individual entry is damaged — use your OS extractor, which reports which file failed, and re-download from the source.
Is the file uploaded? No. All checks run locally in your browser.