🛠️ PDF300
Try to repair a PDF that will not open
A download cut short, a bad USB stick, a crash mid-save. The file is there but the reader refuses it. This tries to read what survived and build a working file around it.
Open the toolRuns on our server — the file is uploaded, processed and sent back.
How it works
- Add the broken PDFThe file is sent to the server.
- Let it rebuildSome damage cannot be undone. Pages lost in the damage stay lost.
- DownloadSave the rebuilt file if it comes out readable.
Questions
Yes — this one runs on a server, so the file is sent over the network and processed there. If you would rather nothing left your device, use the browser tools on the main page instead.
Neither. No account, no watermark on the output. The practical limit is your device memory — large scanned files use more of it.
Guide: repairing a broken PDF
When you'd use this
A download that was interrupted partway, a file copied off a failing USB drive, a PDF that a crashed program never finished writing — all of these can leave a file that looks like a PDF (the right size, the right file extension) but that no PDF reader will open, usually with an error about the file being damaged or not a valid PDF. This tool rebuilds the file's internal structure from whatever data survived and tries to produce a version that opens again.
How it works, and its limits
A PDF is built from a cross-reference table that tells a reader where each object (a page, an image, a font) lives inside the file, plus the objects themselves. Damage usually hits the cross-reference table or the trailer at the end of the file, while the actual page content earlier in the file is often intact. Repair rebuilds that structure by scanning the file for recognisable objects and reassembling a working table around them. This recovers a great deal in many cases, but it is not guaranteed: if the actual page content itself was overwritten or truncated — not just the index pointing to it — that content is genuinely gone, and no amount of structural repair brings back data that no longer exists in the file.
What to check afterward
Open the repaired file and page through it before relying on it. A partial repair can produce a file that opens but is missing some pages, or where a page renders with missing images where the original data could not be recovered. Compare the page count and spot-check a few pages against what you remember of the original, if you have any record of it.
More questions
No — it recovers what the file's remaining data allows. Severe corruption, especially to the page content itself rather than just the file's index, cannot be undone.
Yes — it only reads the file and produces a new one; your original damaged file is not altered or deleted.
If the file is so damaged the server can't recognise it as a PDF at all, there may be nothing left to recover — check whether a backup or the original source (an email attachment, a re-download) is available instead.
That is usually a font-embedding problem rather than file damage, and may not be something a structural repair resolves. Try re-exporting from the original source document if one is available.