Repair PDF
Rebuild the internal structure of a damaged or badly-made PDF.
When a PDF won’t open or shows errors, ModifyPDF rebuilds its cross-reference table and page tree. If that isn’t possible, it recovers every page that can still be read.
How to repair a PDF
- Choose the damaged PDF.
- Click “Repair PDF”.
- Download the repaired file.
Frequently asked questions
Can every PDF be repaired?
Not always. If the file is severely truncated, only the readable pages can be recovered.
Why won’t my PDF open?
The usual causes are an interrupted download, an email attachment that was cut off, a file saved by buggy software, or a storage error on a USB drive or memory card. Typical signs are a “file is damaged” message, missing pages, or a file that opens in one viewer but not another.
How does Repair PDF fix a file?
It reads the damaged file as far as it can and writes every readable page into a new PDF with a fresh internal structure. If the structure is too damaged for that, pages are re-drawn from what can still be read.
Will the repaired PDF look the same?
When the structure can be rebuilt, pages keep their text and images exactly as they were. Pages that had to be re-drawn look the same but are saved as images, so their text can no longer be selected.
What should I try before repairing?
Download or request the file again. An incomplete transfer is the most common cause of damage, and a fresh copy is always better than a repaired one.
Is it really free?
Yes. There is no sign-up, no daily limit and no watermark added to your files.
Are my files uploaded to a server?
No. ModifyPDF processes files with JavaScript inside your browser. Your documents never leave your device, and nothing is stored after you close the page.
How repair works
ModifyPDF reads the damaged file as far as it can, recovers every readable page and writes them into a brand-new PDF with a fresh internal structure. This fixes many files that show errors, open blank or refuse to open in some viewers.
Limits
Repair can’t recreate content that is missing from the file, such as pages lost in an incomplete download. Recovered images are kept exactly as they were, without recompression.
Common causes of damage
Interrupted downloads, email attachments that were cut off, files saved by buggy software, and storage errors on USB drives or memory cards. Symptoms include “the file is damaged and could not be repaired” messages, missing pages, or a file that opens in one viewer but not another.
Try this first
If the PDF came from a download or email, try downloading it again: an incomplete transfer is the most common cause, and a fresh copy is always better than a repaired one.