Fix and recover corrupted or damaged PDF files
Attempt recovery of a PDF that will not open. Upload the damaged file and the tool rebuilds its internal structure, recovering whatever content is still intact. Free, immediate, and worth trying before you conclude a document is lost.
A PDF is more than a stream of page content — it has an internal index called a cross-reference table that tells the reader where every object in the file is located. When that index is damaged, the reader cannot find anything, and the file appears completely broken even though the pages themselves may be perfectly intact.
The usual causes are mundane. Interrupted transfers — a download that dropped, a copy that failed partway — leave a file that is structurally incomplete. Unsafe removal of storage while a file is being written truncates it. Application crashes during save produce files where the content was written but the index never was. Email systems occasionally alter attachments in transit. Failing drives corrupt sectors, which may or may not fall in an important part of the file.
The distinction is straightforward once stated. Repair rebuilds structure. It cannot restore missing data.
If the page content is still in the file but the index pointing to it is damaged, recovery works well — the tool scans the file directly, locates the page objects, and constructs a valid document around them. This is the most common corruption scenario and it usually recovers completely.
If part of the file was never written — a download that stopped at 40%, a copy that failed halfway — then the missing pages do not exist anywhere in the file. No tool can recover them, because there is nothing to recover. What repair achieves in that case is salvaging the portion that did arrive, which is frequently still worth having.
Anyone whose download failed and produced a file that will not open. Offices retrieving old archives where files have degraded on ageing storage. People recovering from a crash that interrupted a save. Anyone sent a file that will not open when the sender is unavailable to resend it. Students and researchers facing a corrupted document with a deadline approaching.
Upload the damaged file by dragging it onto the box or clicking to browse. The tool analyses what is present and rebuilds a valid document from the recoverable content. Download the result and open it.
Check every page rather than assuming the first one being fine means the document is whole. Partial recovery is a real outcome, and it is better to know immediately which pages are missing than to discover it later when you need them.
A few quick checks occasionally solve the problem without any repair at all.
Try a different reader. Some readers are far more tolerant of minor structural irregularities than others. A file that Acrobat rejects sometimes opens perfectly in Chrome, Firefox, or macOS Preview.
Check the file size. If it is very small — a few kilobytes for what should be a large document — the transfer clearly failed and re-downloading is more likely to help than repairing.
Try downloading again. If the file came from the web or a shared drive, a fresh copy is the simplest fix and takes less time than any recovery attempt.
Save a backup copy somewhere separate immediately. A file that has been corrupted once is a signal worth heeding — it may indicate a failing drive, an unreliable network connection, or a storage device that should be replaced. Recovering the document is the immediate problem; not losing it again is the one worth addressing next.
If pages were lost, Merge PDF can combine the recovered portion with a replacement section if you can obtain one from another source.
Your file is processed in memory and discarded the instant your download completes. Nothing is written to disk, nothing is logged, and no copy is retained.