TROUBLESHOOTING · REVIEWED AUGUST 25, 2026 · SAKSHI KUMARI

PDF troubleshooting: a practical check list

If a PDF will not open, upload or process, keep the original safe and work through one check at a time.

Start here

1. Check the file type: confirm it is actually a PDF and that the filename was not merely renamed.
2. Open it locally: if it fails in a standard viewer, download it again from the source or ask for a new copy.
3. Check protection: password-protected PDFs cannot be processed by many browser libraries. Use authorised access instead of trying to bypass it.
4. Check size and pages: tool limits and device memory can stop a large scan even when the PDF is valid.
5. Try a current browser: close unnecessary tabs, retry once, and avoid repeating changes to the only copy.

When the output looks wrong

Review page order, rotation, blank pages and image clarity. For a scan, return to the original image where possible rather than compressing an already degraded PDF repeatedly. For a missing font, form field or complex layout, use the source application or a compatible desktop PDF program.

Repair limits

The PDF Repair page attempts a browser-side rebuild. It cannot recover content that is absent or correctly interpret every damaged, encrypted or advanced PDF. If a document is important, obtain a fresh authorised copy.