Repair Corrupted ZIP

How to use Repair Corrupted ZIP

A ZIP archive has two parallel sources of information: each entry has a local header right before its compressed data, and at the very end of the file there is a central directory that lists every entry. If the central directory is truncated, overwritten, or damaged in transit, standard unzip tools bail out even though most of the file data is still perfectly readable. This tool exists to pull those intact entries back out.

Drop the broken .ziponto the dropzone. The tool first tries a normal decode with CRC checks disabled, which is enough to rescue most "incomplete download" or "bad CRC" cases. If that still cannot find a valid central directory, it falls back to a byte-level scan for local file header signatures (PK\x03\x04) and reconstructs entries one at a time using the sizes and filenames it finds inline.

Every recovered entry is written into a fresh ZIP that is built from scratch with a correct central directory. Broken entries — those whose compressed data could not be inflated, or whose sizes are not in the local header because the archive was created in streaming mode — are listed separately so you can see exactly what was left behind. The original file on your disk is never modified; the repaired copy downloads as yourname-repaired.zip.

No file ever leaves your machine. The damaged archive is read into the tab, scanned with plain JavaScript and the browser's built-in DEFLATE decoder, and the rebuilt ZIP is handed back to you as a download. Archives that were created in streaming mode (where each entry's size lives in a separate data descriptor) or that use zip64 extensions for files larger than 4 GB may partially recover; everything else usually comes through cleanly.