Repair a PDF that will not open, print or upload

Most damaged PDFs are structurally damaged rather than lost: a cross-reference table pointing at the wrong byte offsets, a truncated download, a stack of incremental saves from a form somebody saved thirty times, an object graph carrying unreachable rubbish. A parser can usually find its way through that; the file just drags the wreckage around and some software refuses it. This imports every page it can read into a brand-new document and rebuilds the file around them, so what comes back contains only what was actually reachable. What it cannot do is invent bytes that were never there.

It cannot invent data that is not in the file. A download that stopped half way is missing the second half, and no rebuild puts it back — the pages that arrived come back and the notes name the ones that did not.

Repair a PDF

No account. Your upload is deleted after 2 hours, the result after 24 hours.

How it works

  1. Upload the file that is misbehaving. There is nothing to configure. The tool reads what it can and writes a clean file around it, page by page, with a fresh cross-reference table.
  2. Read the notes before you rely on the result. They say how many pages were rebuilt, which pages were left out because nothing readable was there, how many bookmarks survived and whether any of them now point nowhere, and what could not be carried over at all.
  3. Open it in the software that refused the original. That is the real test. A file that opens in one reader and is rejected by another is exactly the case this fixes, and the only way to know is to try it there.

What this tool does not do

  • It cannot invent data that is not in the file. A download that stopped half way is missing the second half, and no rebuild puts it back — the pages that arrived come back and the notes name the ones that did not.
  • It does not decrypt anything. If the original was password-protected, the protection cannot be carried over and the notes say so; unlock it first if you need it protected afterwards.
  • It does not repair the contents of a page. A figure that renders as a grey box because its image data is corrupt still renders as a grey box.
  • Interactive extras can be lost — JavaScript, embedded attachments, some annotations and unusual structures — and the notes list what did not make it.
  • A digital signature does not survive. The file is rebuilt from scratch, which is the whole point, and a signature covers the bytes of the file it was applied to.
  • If not one page can be read, the job stops and tells you so rather than handing you an empty document.

What happens to your file

The file is uploaded because Repair PDF runs on our server rather than in the browser tab. It is kept for at most 2 hours and the result you download for 24 hours, then a scheduled job deletes both — a job has to be able to read the file while it runs, and you have to be able to retry a failed conversion without re-uploading. Neither needs longer.

Nothing about the contents is logged, and no one reads your documents. The retention page lists the same numbers the code enforces, and the privacy policy says who can reach the storage they sit in.

Questions

Acrobat says the file is damaged and could not be repaired. Will this help?
Often, yes. That message usually means Acrobat’s index into the file is wrong rather than that the pages are gone. This ignores the index entirely, walks the objects it can reach, and builds a new index from what it actually found.
My download stopped half way. Can you recover the rest?
No. The missing part was never in the file you have, and nothing can reconstruct it. What you get is the pages that did arrive, in a document that opens cleanly, plus a note naming the pages that were not there.
The rebuilt file is much smaller. Has it lost something?
Usually not. A PDF saved thirty times carries every earlier version inside it, and rebuilding leaves everything unreachable behind by construction. The notes list anything that genuinely could not be carried over, and the size note tells you how much wreckage was dropped.
Will my form still work afterwards?
Form fields are carried across where they can be, and the notes say when they could not. If the form was the damaged part, expect to lose it — copy the values you need out before you rely on the rebuilt file.
What happens to my bookmarks?
They are re-pointed at the rebuilt pages, because their destinations name the old ones. Where a bookmark pointed at a page that could not be read, it is kept and the notes tell you how many now open nothing — a bookmark that says so is better than one that silently jumps to the wrong place.
Can it repair something that is not a PDF at all?
No. If the bytes are not a PDF — a renamed .docx, an HTML error page saved with the wrong extension — there is nothing to rebuild and the job stops rather than producing a document.