PDF won’t open — what to do
Often the file is damaged, for example by an interrupted download. Upload it above: the tool rebuilds the file structure and rescues readable pages. If that doesn’t help, one of the causes below is usually the reason.
Choose files
or drag and dropPDF
Your files never leave your device — everything runs locally in your browser.
How it works
- 1
Upload the file
The PDF that won’t open.
- 2
Repair
The structure and cross-references are rebuilt.
- 3
Check
Open the repaired file in a PDF viewer.
- 4
Rule out causes
Otherwise go through the checklist below.
Common causes
| Symptom | Likely cause | Fix |
|---|---|---|
| “File is damaged” | Download or transfer interrupted | Repair, or download again |
| Password prompt | The file is encrypted | Ask the sender, then unlock |
| File is 0 KB | The file is empty | Request it again — nothing to repair |
| Opens only in some programs | Format errors in the PDF | Repair |
| .pdf extension, but not a PDF | Wrong file type | Open with the right program |
What a repair can and can’t do
At its end, a PDF contains a kind of index pointing to all objects in the file. If that index is broken, many programs refuse to open the file although the pages are still intact. The repair rebuilds the index. If parts of the file are missing because a download stopped halfway, the lost pages can’t be recovered.
Tips
- Nothing can restore content that is missing from the file — for interrupted downloads, downloading again often helps.
- Test the repaired file in a second PDF viewer.
- Always work on a copy of the original file.