Can I fix a truncated ZIP file without any software?

No. Standard ZIP tools cannot open a truncated file because the central directory is missing. You need a repair tool that reads local headers to extract the surviving files.

Will the recovered files be damaged?

Files that were stored before the cut point are usually intact and usable. The file being written when the cut happened will be incomplete and cannot be used.

How do I know if my file is truncated or just corrupted?

Compare the file size with the original size. If your file is smaller, it is truncated. If the size matches but the file still gives errors, it may be corrupted in a different way.

Does WinRAR show a different error if the file is truncated?

Yes. WinRAR shows "Unexpected end of archive" for truncation. For files it cannot read at all, it shows "The archive is either in unknown format or damaged".

Fix "Unexpected End of Archive" in a ZIP File

"Unexpected end of archive" means the ZIP file was cut short. The transfer stopped before all the data arrived. The file you have is incomplete. This is a truncated archive, and the central directory, stored at the very end of the file, is almost certainly missing. You can still recover some of the contents.

What a Truncated Archive is

A truncated archive is a ZIP file missing its tail end. ZIP files store a central directory, like a table of contents, at the very end of the file. When a file is cut short, that directory is usually lost first. Without it, archiving tools like WinRAR or 7-Zip cannot read the file normally. WinRAR reports this as "Unexpected end of archive" or, for files it cannot read at all, "The archive is either in unknown format or damaged". 7-Zip shows a similar message: "Unexpected end of data". The file is not necessarily damaged in the parts that did arrive. The missing directory makes it unreadable by standard means.

How to Confirm Truncation by Comparing Sizes

Check the File Size

The most reliable confirmation is comparing the size of the file you have with the original file size. Here is how:

Check the source where you got the file. Many download pages or email messages show the original file size. Write it down.
Check the size of the file on your computer. On Windows, right click the file and select Properties. On macOS, select the file and press Command+I. On Linux, use ls -l in the terminal.
Compare the two sizes. If your file is smaller, it is truncated. The difference tells you how much data is missing.

Spot an Incomplete Transfer

If you cannot find the original size, look at the download behaviour. Unfinished browser downloads leave temporary files. Chrome uses .crdownload, Firefox uses .part, and Safari uses .download. Seeing one of these extensions means the transfer never finished.

What Can and Cannot Be Saved from a Truncated ZIP

A truncated ZIP file can still contain usable data. The files stored before the cut keep their local headers. Their content is intact. You can recover those files. The file being written when the cut occurred is incomplete and cannot be saved. Data that never arrived cannot be reconstructed by any tool. No software can guess the missing bytes.

If a ZIP contains ten files and the truncation cut during the seventh file, the first six files are likely recoverable. The seventh file will be partial or missing. Files eight through ten are gone entirely.

What a Repair Tool Can Do

A specialised repair utility scans the truncated ZIP, finds the local headers of the files that did arrive, and extracts them. This bypasses the missing central directory. The result is a folder with the files that survived. The incomplete file and any files after the cut are lost.

What a Repair Tool Cannot Do

A repair tool cannot recreate missing data. It cannot fix the incomplete file. It cannot recover files stored after the cut point. If the truncation happened early in the archive, very little may be salvageable.

Why Re-downloading is Usually Better

Get the file again from the original source if you can. A fresh transfer gives you the complete, undamaged archive. Repair is a fallback for when the source is gone, the link is dead, or the file was sent to you and the sender no longer has it. Repair saves you time only when you cannot get the file again. In all other cases, re-downloading is the simpler and more reliable option.

How to Prevent Truncation in the Future

Truncation happens because of interrupted transfers. Reduce the chance:

Use a download manager that can resume interrupted transfers.
Make sure your internet connection is stable before starting a large download.
Check available disk space. A full disk can stop a download midway.
If you are transferring a ZIP file via email or cloud storage, confirm the upload finished before downloading.

Using a ZIP Repair Tool as a Last Resort

If getting the file again is not possible, try a repair tool. Sites like zip.repair offer an online option to recover files from truncated archives. The tool reads the local headers of the files that arrived and extracts them. You will get back whatever data survived the cut. The incomplete file and any missing files cannot be recovered. Data that never arrived cannot be reconstructed by any tool.