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ToolSuite
File & Archive Tools

Test ZIP Integrity

Verify that every entry in a ZIP decompresses cleanly and matches its stored checksum.

or drag it here

.zip, application/zip · up to 200 MB

Processed in your browser

Fill in the form and press “Test archive” to see the result here.

How to use it

  1. 1Select your file, or drag and drop it onto the upload area.
  2. 2Adjust the options if you need something other than the defaults.
  3. 3Press the button. Everything happens on your device.
  4. 4Download the result.

About the Test ZIP Integrity

Every entry in a ZIP stores a CRC32 checksum of its uncompressed contents. This decompresses each entry, recomputes the checksum and compares - which is exactly what a desktop archiver does when it tests an archive.

A failure tells you which entry is damaged. The usual cause is a truncated download, in which case the central directory at the end of the file will also be missing.

Questions people ask

Is your file uploaded to a server?

No. This tool runs entirely in your browser using standard web APIs, so your file never leaves your device. You can confirm it by opening your browser's network panel while the tool runs, or by disconnecting from the internet after the page has loaded.

Is it free, and do I need an account?

Yes, it is free, and there is no account, no sign-up and no watermark on the result. The project is funded by optional donations.