Compress PDF
Why a PDF upload fails and how to fix it
Diagnose common upload failures including file size, password protection, damaged PDFs, unsupported formats, browser issues, and network interruptions.
This guide is for users whose PDF or image upload fails before processing or whose output is not generated as expected.
Check the file basics
Start with the simple causes: wrong file type, file size above the limit, too many selected files, or a file extension that does not match the real content.
If the tool accepts one PDF only, uploading a folder, ZIP, document file, or image will fail. Use the matching converter first when the source is not already in the expected format.
Look for protection or corruption
Password-protected, restricted, or damaged PDFs are common reasons for failed processing. Try opening the file locally and exporting a fresh copy before uploading again.
If the PDF opens slowly or displays errors in a desktop viewer, fix the source file before trying online processing. A converter cannot reliably repair every broken document.
Reduce the job size
Large uploads can fail because of browser memory, network interruption, or server limits. Split the document into smaller batches or remove pages that are not needed.
For image batches, process similar files together. Mixing very large photos with small screenshots can make the job harder to review and repeat if one file causes a problem.
Retry carefully
Refresh the page only after saving any file order or source changes you need. Try a modern browser, a stable connection, and a shorter filename if the same upload keeps failing.
If an output downloads but looks wrong, return to the source file and check page rotation, scan quality, and whether the document contains unusual embedded content.
Quick checklist
- Confirm the file type and size limit.
- Remove password protection before upload.
- Split large jobs into smaller batches.
- Try a clean source export if the PDF is damaged.