What Repair PDF does
When a PDF reader says a file is damaged or cannot be opened, the pages are often still inside — it is the file's internal index that is broken. Repair PDF rebuilds that structure. If rebuilding is not enough, it tries a second method: re-creating each page that can still be read. You get a new file and a report of what was recovered.
How to repair a PDF
- Add the damaged PDF.
- Press the button. The tool analyses the file and attempts the repair.
- Read the result: it states how many pages were recovered and which method worked.
- Download the repaired file and check it page by page.
How PDFs get damaged
- A download or upload stopped before the file was complete.
- An e-mail system or messaging app altered the attachment.
- The file was saved to a failing USB stick or memory card.
- The program that created it crashed while saving.
- The file was opened and saved as text by mistake.
What can and cannot be fixed
| Problem | Chance of repair |
|---|---|
| Broken cross-reference table (the index of the file) | Good — it can be rebuilt by scanning the file |
| Extra data before or after the PDF content | Good |
| A few damaged objects | Partial — readable pages are recovered |
| File cut off part-way | Pages stored before the cut may be recovered |
| File is empty, or its content was overwritten | None |
If the page data itself is missing, nothing can bring it back, and the tool tells you when no readable pages were found. No repair tool can do more than recover what is still in the file.
Check the repaired file
- Count the pages and compare with what you expected.
- Look for missing images or fonts that have been replaced.
- When pages had to be re-created, they may be stored as images; text on those pages will not be selectable. PDF OCR can add a text layer again.
Before you try a repair
The quickest fix is often a fresh copy.
- Download the file again, or ask the sender to resend it — ideally in a ZIP archive, which protects it in transit.
- Try a different PDF reader. Some are more tolerant than others.
- Make sure the file really is a PDF. A file of 0 KB, or an HTML error page saved with a .pdf name, cannot be repaired.
Is the file locked, not broken?
A password prompt is not damage. If the document asks for a password, use Unlock PDF with the correct password.
Tips
- Work on a copy and keep the damaged original until you are satisfied with the result.
- If only some pages come back, merge them with pages from another source, such as an older version.
- Inspect a recovered file's details with PDF Metadata Viewer.
Privacy
The repair runs in your browser. The file is not uploaded to our server.