03 / HOW TO REPAIR A DA
How to repair a damaged PDF
Using Repair PDF is a single step: upload the PDF file that will not open or shows errors. The file may be up to 50 MB and 500 pages. The tool accepts exactly one file per job; there are no settings to adjust, because the damaged file itself is the only input the repair needs.
After upload, the file is scanned for malware and its type is confirmed from the actual bytes - renaming a non-PDF to .pdf will not get it through. The repair then runs on the server, so the work happens away from your device.
04 / WHAT HAPPENS TO YO
What happens to your damaged file
The uploaded file goes to private object storage and is deleted after 1 hour if you are not signed in, or 7 days if you are signed in. While the job runs, the page shows uploading, then queued, then running with a percentage, so you can see that work is happening even if the file is large.
Repair PDF tries two independent methods. First, the qpdf engine attempts a full rebuild of the cross-reference table and any damaged object streams. If qpdf refuses the file outright, a second pass salvages every page that can still be read and writes a new document around them.
The repaired file is then opened again and its pages are counted before it is offered for download. If nothing readable came out, the job fails rather than handing you a file that is still broken.
05 / WHAT REPAIR PDF CA
What Repair PDF cannot fix
No repair can invent content that was never in the file. A truncated download is missing the pages it never received - Repair PDF does not recreate them. If the source file simply does not contain part of its own content, that content will be absent from the repaired PDF.
This tool also does not handle encrypted PDFs. An encrypted PDF is locked with a password - that is a different problem. Use a password-removal tool first and then repair the resulting file if needed.
When Repair PDF does succeed, you get a structurally sound PDF with all pages that could be recovered. Pages that were too badly damaged to read will be missing, and there is no way to know which pages were lost except to look through the output.
06 / WHEN THE REPAIRED
When the repaired PDF still looks wrong
If the repaired file opens but some pages are blank, missing, or show garbled text, that means those parts of the original file were damaged beyond recovery. The repair salvaged every page that had enough intact data to be read; the rest could not be brought back.
Check whether the source file itself is complete. If it came from an interrupted download, an email attachment that failed, or a cloud sync error, try obtaining a fresh copy of the original PDF. Repair PDF can only work with the bytes you give it.
If the original PDF was very large or had many complex objects - such as extensive annotations or embedded multimedia - a repair may drop some of those elements even when pages survive. The goal is a readable document, not a perfect replica of every internal object.
07 / REPAIR PDF IS NOT
Repair PDF is not a converter
Repair PDF is strictly for fixing a PDF that is already supposed to be a PDF. It does not convert other formats into PDF and it does not change PDFs into another file type. If the file you have is not actually a PDF - even if it is named .pdf - the tool will reject it before any repair begins.
Because the job is server-side, the size of the file does not slow down your own device. The only limits are the 50 MB file size and 500 page count; files that exceed either will not be processed.
FAQ
Common questions
How do I repair a corrupted PDF file?
Upload the damaged PDF to Repair PDF. The tool rebuilds the cross-reference table and recovers readable pages. You get a repaired PDF if any content can be salvaged. Upload only one file per job.
Why won't Repair PDF open my PDF?
Repair PDF skips files that are not PDFs (based on content, not name) and encrypted PDFs. If your file is encrypted, remove the password first with a dedicated unlock tool. If it is not a PDF, convert it to PDF first.
Will Repair PDF reduce the quality of my PDF?
No. Repair PDF rebuilds the file structure without resampling images or altering text. It salvages pages from the source. If certain elements were damaged, they may be missing, but for pages it recovers, the quality remains as in the original.
Why are some pages missing from the repaired PDF?
Those pages were too damaged for the tool to read. A second pass salvages whatever pages are still readable. If data for a page is absent - for example, from a truncated download - it is impossible to recreate.
What is the maximum file size or page count for Repair PDF?
The file can be up to 50 MB and up to 500 pages. If your file exceeds either limit, it will not be processed. Only one file per job is accepted.