Free tool · 100% private
Repair PDF
Fix a damaged or won't-open PDF by rebuilding its structure. Everything runs inside your browser: your file is never uploaded, so nothing can leak. It rebuilds broken cross-reference tables and trailers on your device — and if a file is too far gone, it tells you honestly instead of handing you a broken one.
Choose a damaged PDF or drop it here
One PDF · it stays on your device
Repair fixes structural corruption — a broken cross-reference table, a damaged trailer, a wrong
startxref offset, or a file a reader refuses to open even though the pages are intact. It can't rebuild bytes that are genuinely missing (a truncated download, or damage inside the page content) — if it can't produce a valid file, it will say so rather than hand you a broken one.Repairing your PDF…
Working entirely on your device
🔒 Nothing is uploaded — the diagnosis and repair stay on your device
- ✓Reading your PDF on this device
- ✓Diagnosing what's broken
- ✓Rebuilding the structure with two engines
- ✓Verifying the result re-opens
Repaired & verified
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How to repair a damaged PDF (without uploading it)
Most "repair PDF" websites upload your file to their servers, rebuild it there, and send it back — which means your (possibly sensitive) file briefly lives on someone else's machine. This one is different: it does the whole job on your device, with real repair engines, and it checks its own work before handing you the file.
- 1Add your broken PDF. Drag it onto the box or click to pick. It loads straight into your browser's memory — nothing is sent anywhere.
- 2Diagnose & rebuild. Your browser runs a structural check, then rebuilds the cross-reference table and trailer with the qpdf engine and, as a fallback, pdf-lib's lenient parser.
- 3Verify & download. The recovered file is re-opened and its pages counted on your device. You only download a PDF that has been verified to open — never a broken one.
Honest by design. A browser can rebuild a broken structure, but it can't invent bytes that are truly gone. If your file lost data — a half-finished download, or damage inside the page streams — this tool won't fake a repair. It tells you the file is too damaged, so you don't waste time on a PDF that only looks fixed.
Frequently asked questions
Is my PDF uploaded to a server?
No. This tool runs 100% in your browser. Your file is read into your device's memory and repaired locally — it's never sent to any server, so there's no way for it to leak. It even works offline once the page has loaded.
What kinds of damage can it fix?
It fixes structural corruption — a broken or missing cross-reference (xref) table, a damaged trailer, a wrong
startxref offset, or a PDF a reader refuses to open even though the page data is intact. It rebuilds the file's structure using the open-source qpdf and pdf-lib engines running on your device.Can it recover a file that lost data?
No — and it won't pretend to. If bytes are genuinely missing or overwritten (for example a partial or truncated download, or damage inside the page content), that data can't be rebuilt without the original. The tool verifies its result and, if it can't produce a valid PDF, tells you honestly instead of handing over a broken file.
How do I know the repaired file actually works?
Every repaired file is re-opened and its page count confirmed on your device before you can download it. If it doesn't re-open cleanly, you never get it — you only download a PDF that has been verified to open.
Is it really free?
Yes — completely free, no sign-up, no watermark, no account limits. It's part of AttendFlow's free student tools.
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