About the Repair PDF
Repair PDF tries to rebuild a PDF that will not open, is reported as damaged, or stops halfway. It first looks at the file for the usual signs of trouble, such as a missing end, a broken page index or extra bytes at the start. It then uses qpdf, a well-known PDF library running inside your browser, to rebuild the file's structure. If the page index is gone completely, the tool rebuilds it from the objects it finds in the file. As a last step it copies out whatever pages can still be read into a fresh file. Every result is opened again to check that it has pages before you can download it. Nothing is uploaded. Repair cannot bring back text or pictures that are actually missing, and it cannot open a password-protected file.
Updated September 2026
How to use the Repair PDF
- 1Select the damaged PDF, or drop it on the page.
- 2Read what the tool sees, for example that the end of the file is missing.
- 3Press Repair PDF and wait a few seconds.
- 4If it works, download the repaired file and open it to check the pages.
- 5If it says the file is too damaged, try the original download again or ask the sender for a fresh copy.
Signs that a PDF is damaged
- It will not open, or your reader says the file is damaged or not a valid PDF.
- It opens with fewer pages than you expect, or pages are blank.
- The file size is much smaller than the original you were sent.
- An email or chat app changed the file's name or opened it as text.
- The download stopped before it was finished, or the phone lost signal during saving.
What Repair PDF does, step by step
First the tool reads the raw bytes and reports what it can see: whether the PDF header is present, whether the file ends properly and whether the page index is there. This gives you a plain-English idea of what happened before anything is changed.
Then it tries the gentlest fix. qpdf, a mature open-source PDF library, reads the file and writes a clean new copy with a rebuilt index. If qpdf cannot start because the trailer at the end is missing, the tool searches the file for its objects and the document catalog, writes a new index and trailer, and gives that to qpdf. If that also fails, it copies every page it can read into a new file.
The repaired file is opened once more to make sure it has at least one page. Only files that pass this check are offered for download, so you are never given a file that is still broken.
If repair does not work
Download the file again, preferably on a stable connection, and compare the size with the original. Ask the sender to send it again as a zip file, because some apps damage attachments. If the PDF came from a scanner or a phone app, export it again from there.
If a file is locked with a password, use Unlock PDF first. If you only need the pictures from a damaged file, Extract PDF Images can sometimes still find them, and PDF OCR can read text from a scan. To keep a rebuilt file small and quick to open, run it through Compress PDF or Web Optimize PDF afterwards.
Tips for phone and computer
On a phone, choose the file from Files or your download folder, press Repair PDF and save the result again. On a computer, drag the file onto the page. Large scans of hundreds of pages take longer, so keep the tab open until you see the green message.
To avoid future damage, wait for downloads to finish before opening files, do not rename the extension, and keep a backup of important documents. Fixing a file changes only the copy you download, and your original is never touched.
Features
- Checks the start, end and page index of the file
- Rebuilds the cross-reference table with qpdf
- Rebuilds a missing page index itself when qpdf gives up
- Removes junk bytes before the PDF header
- Copies the readable pages when nothing else works
- Checks that the repaired file opens and counts its pages
- Runs in your browser: your file is never uploaded
Frequently asked questions
Why does my PDF say it is damaged or corrupted?
The most common reasons are an interrupted download, a copy that stopped early, a file saved by faulty software, or a transfer that added or removed bytes, such as some email or chat apps. A PDF keeps a page index near its end, and if that part is missing or wrong, many readers refuse to open the file even though the pages are still inside it.
Can every damaged PDF be repaired?
No. If the page index is broken but the pages are still in the file, repair usually works. If part of the file's content is gone, for example because a download stopped halfway, the pages that were in the missing part cannot be recovered. The tool tells you clearly when it cannot rebuild the file.
What does the error about the cross-reference table mean?
The cross-reference table, or xref, is the index that tells a PDF reader where every page and picture sits in the file. When it is missing or its numbers are wrong, readers report messages such as 'xref table not found' or 'the file is damaged and could not be repaired'. Repair PDF rebuilds this index from the objects in the file.
Is my file uploaded to a server?
No. The repair runs in your browser, and the file never leaves your device. This is useful for private documents such as contracts, statements and medical letters.
Will the repaired PDF look the same as the original?
When the structure is rebuilt with qpdf or from the page index, the pages are kept as they are, so they look the same. In the last-resort mode the readable pages are copied into a new file, and a few extras such as bookmarks, links and form fields can be lost. The tool says which method was used.
What if the PDF asks for a password?
A password-protected file is not damaged, it is locked. Use Unlock PDF and enter the password, then use Repair PDF on the result if it still has problems.
Can I fix a PDF that opens but shows blank or garbled pages?
Sometimes. If the structure is the problem, the rebuilt file may show the pages correctly. If the page contents themselves are damaged, or a font is missing, the text can still look wrong after repair, and you may need a fresh copy of the file.