How do I fix a corrupted PDF that will not open?
To repair a corrupted PDF, upload it to FixDoks's Repair PDF tool and click Repair PDF. The server rebuilds the file's broken index, or redraws each readable page when the structure is too damaged, then tells you which method it used. Your file is uploaded over HTTPS and deleted right after the repaired copy is returned.
Repair PDF at a glance
| Input | Damaged PDF |
|---|---|
| Output | Repaired PDF |
| Processing | On our server over HTTPS; files are deleted right after conversion |
| Max file size | 50 MB per file |
| Price | Free, no watermark |
| Download | Free Google sign-in |
| Works on | Chrome, Edge, Safari and Firefox on Windows, Mac, Android and iPhone |
How to use Repair PDF
- Click Select damaged PDFs and pick the file that will not open properly.
- Click Repair PDF. The structure is rebuilt on our server.
- Download the repaired file and check that all pages are there.
Why do PDFs get damaged?
A PDF has an index at the end (the cross-reference table) that tells a viewer where every page, font and image is stored. When a download is interrupted, an email attachment is cut short, a USB drive is removed too early, or a buggy program writes the file, that index can be wrong or missing. The viewer then says the file is damaged, shows blank pages, or refuses to open it at all, even though most of the content is still inside.
How does the repair work?
FixDoks tries two methods, from gentle to thorough:
- Structure rebuild: the file is scanned from start to finish, every object is found, and a fresh, correct index is written. This fixes most "file is damaged and could not be repaired" errors while keeping text, links and bookmarks intact.
- Page redraw: if the structure is too broken, each readable page is interpreted and redrawn into a brand new PDF with Ghostscript. Some interactive features may be lost, but the visible content is saved.
You get a note telling you which method was used and how many problems were fixed.
What can and cannot be recovered
- Usually recoverable: broken or missing index tables, wrong offsets, files with junk at the start or end, incomplete saves.
- Partly recoverable: truncated downloads. Pages that were fully downloaded come back; pages after the cut are lost.
- Not recoverable: files that are empty, overwritten with zeros, or not actually PDFs (for example an HTML error page saved with a .pdf name).
Try this first
- Download the file again from the original email or website: a fresh copy is always better than a repaired one.
- Try opening it in a different viewer such as Chrome or Firefox, which are quite forgiving.
- If the PDF asks for a password rather than showing an error, it is protected, not damaged. Use Unlock PDF with the password.
After repairing
Check every page of the repaired file. If it is large, Compress PDF can shrink it, and PDF to PDF/A makes a robust archive copy.
Preventing damaged PDFs
- Wait for downloads to finish completely before opening or moving the file.
- Always eject USB drives and memory cards safely.
- Avoid editing the same PDF in two programs at the same time.
- Keep backups of important documents in cloud storage or a second drive.
The damaged file and the repaired copy are deleted from our server straight after the download.