Repair PDF
Fix a PDF that won't open or shows errors, and recover the pages that can still be read.
or drop a file here
Processed on your device – files are never uploaded
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Created on your device. Nothing was uploaded.
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PDFs get damaged by interrupted downloads, failing disks, email gateways or buggy software. Often the pages are still inside the file, but the index that tells a reader where to find them is broken. PDF4U rebuilds that structure and saves a clean copy.
Repair first runs the file through the open-source QPDF engine, which fixes problems such as wrong stream lengths and broken references. If the file can't be opened at all, PDF4U scans it object by object, rebuilds the cross-reference table and the page list, and keeps every page it can find. All of this runs in your browser.
Signs that a PDF is damaged: the reader says the file is damaged or can’t be opened, pages show up blank, the file opens in one app but not in another, or other PDF tools refuse it. Before repairing, try downloading the file again – if the source is fine, a fresh copy is the quickest fix.
How to repair a damaged PDF
Select the damaged PDF
Click “Select PDF file” or drop the file onto the page. It's fine if no preview appears.
Repair
Click “Repair PDF”. If the file is password-protected, you'll be asked for the password.
Check and download
Click “Download” and open the repaired file. Check that all the pages you need are there.
Frequently asked questions
What kinds of damage can be repaired?
Broken or missing cross-reference tables, wrong offsets, files cut off at the end, junk before or after the PDF data, wrong stream lengths and damaged page lists. Content that is missing from the file can't be brought back.
Why are some pages missing or blank after repair?
When part of a file is lost, for example in a download that stopped halfway, the pages stored in that part are gone. PDF4U recovers everything that is still in the file.
Is my file uploaded for repair?
No. The repair runs in your browser on your device, so even confidential documents stay private.
Can I repair a password-protected PDF?
Yes, if you know the password. The repaired file keeps its protection.
The repaired file still has problems. What else can I try?
Open the original in a different PDF reader and save or print it to a new PDF, or ask the sender for a fresh copy. Repairing that new copy often helps.
Does repairing change pages that are fine?
No. Pages that are intact are kept as they are; the repair rebuilds the file structure around them and saves a clean copy. Your original file is not changed.