PDF Repair Tool — Fix a Corrupted PDF
Diagnose and repair a damaged PDF in your browser. Tells you exactly what is wrong before it tries anything.
Reading the file…
How to use this tool
- Select the damaged PDF, or drag it onto the box above.
- It is checked first — header, end-of-file marker, cross-reference pointer, encryption and object count — and the findings are shown before anything is altered.
- Repair runs automatically: a lossless structural rebuild first, page-by-page recovery only if that fails.
- Download the repaired file. The panel tells you which method was used.
Most PDF corruption is structural rather than missing data. A PDF ends with a cross-reference table listing where every object sits; when that breaks, readers refuse a file whose contents are almost entirely intact. Rebuilding it is genuinely possible, and it is lossless.
The specification
| Diagnoses | Header, end-of-file marker, cross-reference pointer, encryption, object count |
|---|---|
| Repair 1 | Structural rebuild — lossless, text stays selectable |
| Repair 2 | Page-by-page recovery if the structure is beyond rebuilding |
| Cannot fix | Genuinely missing bytes — a truncated download |
| Limit | 100 MB |
Why uploads get rejected
Meeting the size is only part of it. These are the failures that actually come up:
- The download was interrupted, so bytes are actually missing. Nothing can invent them — download the file again from the source, which does fix this.
- The file is password-protected. Remove the password first; we do not bypass encryption.
- The file is not a PDF at all. A renamed Word document or image shows up as "no PDF header".
- The file is 0 bytes. There is nothing inside it.
How it works
The file is diagnosed before anything is changed. The raw bytes are checked
for the %PDF- header at the start, the %%EOF marker at
the end, a startxref pointer, an /Encrypt dictionary,
and how many PDF objects are actually present. Those five checks distinguish the
common failures from each other, and you see the findings before repair runs.
Repair then makes two attempts, in order. The first is a structural rebuild: the document is parsed with lenient settings, its objects are copied into a fresh document, and a clean cross-reference table is written. This is lossless — text stays selectable, images keep their quality — and it fixes the most common cause of a PDF that will not open, which is a broken index rather than missing content.
If the structure is too damaged for that, the fallback renders each page it can reach and assembles those images into a new PDF. This recovers pages that would otherwise be lost, but it flattens them: text becomes part of an image. The result panel tells you plainly which method was used, because the difference matters to what you can do with the file afterwards.
One thing repair cannot do is invent data. If a download was interrupted, the missing bytes are not anywhere in the file and no tool can reconstruct them.
Who uses this
A PDF that will not open, opens blank, shows "damaged file" in Acrobat, or was recovered from a failing drive or an interrupted transfer.
Other names for this tool
People look for this under several different names. If you arrived searching for any of the following, this is the right page — they all describe the same thing:
- repair pdf online
- pdf repair tool free
- fix corrupted pdf
- recover corrupt pdf file
- pdf recovery online
- restore damaged pdf
- repair pdf file free
- corrupted pdf fixer
Frequently asked questions
Can a truncated PDF be recovered?
Only partly, and only the part that survived. If the download stopped halfway, the rest of the data does not exist anywhere in the file — no tool can reconstruct it. What repair can do is salvage the pages that did arrive. If you still have access to the source, downloading again is a better fix than any repair tool.
Will repair lose my text?
Not on the first pass. A structural rebuild copies the existing objects, so text stays selectable and images keep their quality. Only if the structure is unrecoverable does it fall back to rebuilding pages as images, and it tells you when that happens.
Why does my PDF open in one program but not another?
Readers differ in tolerance. Chrome and pdf.js rebuild a broken cross-reference table on the fly; Acrobat and many print systems refuse. Repairing writes a clean table so every reader accepts it.
Is my file uploaded?
No. Everything runs in your browser — which matters here, because damaged files are often the ones you most want back and least want to send to a stranger.
Is this really free?
Yes — no account, no trial, no watermark and no cap on usage. It runs on your own device rather than our servers, so there is no cost for us to pass on.
Does it work on a phone?
Yes. The interface adapts to phone and tablet screens and everything runs in the browser, so there is no app to install.
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Your files stay on your device. This tool runs entirely in your browser. No file is uploaded, transmitted, or stored. You can verify this by opening your browser's Network tab while using the tool.
Disclaimer. Specifications published by exam boards, governments and platforms change without notice. We verify and date every specification on this site, but you should always confirm against the official source before submitting an application. See our full disclaimer.