How to fix a PDF that won't open or says it is damaged

Drop the file into Repair PDF. It reads the PDF the strict way a reader does; if that fails, it scans the whole file for pages without trusting its broken index and writes a new PDF around every page it finds. The result tells you how many pages came back, then you press Download PDF.

Steps

1. Open Repair PDF and drop the damaged file onto the box, or click to choose it. It is checked and, if needed, rebuilt on your device straight away.
2. Read the bar under the preview. It says either "No damage found", or that the file was rebuilt, with the number of pages recovered and the number the file says it should have.
3. Compare page one of the Original and the Repaired copy.
4. Press Download PDF. Then open the download and look at every page before you rely on it. The original file is not changed.

Why PDFs break

Every PDF ends with an index that says where each part of the file starts. Reader programs jump straight to it. When the index is wrong or missing, the reader gives up with a message such as "the file is damaged and could not be repaired", even when nearly everything else in the file is fine.

Common causes:

• A download or upload that stopped early.
• An email or upload system that changed a few bytes.
• A disk or USB stick error.
• A program that crashed while saving.

What repair can and cannot fix

When the file is healthy, you are told no damage was found and the download is a fresh, tidy copy of the same file. If it still will not open somewhere, the program opening it may be the problem.

What a rebuilt file keeps

A rebuilt file keeps the pages that were recovered, with their text, fonts and images. Bookmarks, form fields and links between pages are not carried over when a file has to be rebuilt. If you need those, ask the sender for a fresh copy and use the repaired one in the meantime.

If nothing comes back

The message "Nothing could be recovered" means the file may not be a PDF at all, or the part that describes its pages is missing. Newer PDFs keep that part near the end of the file, which is exactly what a cut-off download loses. In that case:

1. Check the file size. A PDF of a few KB that should be several MB is a strong sign the download stopped.
2. Download the file again from where it came from, or ask the sender to send it again.

Password-protected files

If the PDF is sound but has a password, enter it and you get a working copy without one. If it is both damaged and password-protected, it cannot be rebuilt without breaking its encryption, and the tool says so. A fresh copy from the sender is the only fix for that case. See Unlock PDF for removing a password you know from a healthy file.

Questions

Can it fix "the file is damaged and could not be repaired"?

Often, yes. That message usually means the index is broken while the pages are still there, and the rebuild finds the pages without the index.

Can it recover a PDF that only partly downloaded?

It recovers the pages that arrived. Pages in the part that never downloaded are not in the file, so no tool can bring them back.

Is the broken file uploaded?

No. The check and the rebuild run in your browser, which matters when the broken file is a contract or a statement.

Is it free?

Yes. There is no sign-up and no limit on how many files you repair.