Files never leave your device.How it works
How to repair a PDF
- 1Drop your PDF above (or click to select).
- 2Click Repair.
- 3Download the rebuilt PDF and try opening it.
Frequently asked questions
- What can this fix?
- It reconstructs the cross-reference table and object structure that many viewers rely on, which recovers files that were truncated, mis-saved, or have a broken index. It can't restore content that was actually lost.
- Does my file get uploaded?
- No. The repair runs entirely in your browser with qpdf — your file never leaves your device.
- My PDF is password-protected — will this work?
- Not directly. Unlock it first, then repair the result.
When a PDF won't open
A PDF can break in ways that have nothing to do with its content: a download cut short, a bad export, or a corrupted cross-reference index that tells readers where each object lives. Repair PDF reads the file with qpdf, which rebuilds that structure as it parses, and writes a clean copy — often enough to make a stubborn file open again.
What it can and can't do
Structural repair recovers files whose bytes are largely intact but whose organization is broken. It cannot invent data that was truly lost — if pages were never fully written, they can't come back. It's always worth a try before giving up on a file.
Notes and limits
Everything runs locally, so even a sensitive document stays on your device. Password-protected files must be unlocked first.
What qpdf actually does when repairing
A PDF viewer normally jumps straight to the file's cross-reference table, an index near the end of the file listing the exact byte offset of every object, to open a document instantly. When that table is missing, truncated, or points to the wrong offsets, most viewers simply give up. qpdf handles this by ignoring the broken index and instead scanning the file's raw bytes end to end, locating every object by its own markers, and rebuilding a fresh, correct cross-reference table from what it finds. The rewritten file is then saved with that clean index in place.
The kinds of damage this fixes
This approach recovers files that were cut off mid-download, saved by buggy or non-standard PDF-writing software, or corrupted by a transfer error, as long as the actual page and content objects survived intact somewhere in the file. It's also worth trying on a PDF that opens but behaves oddly: missing pages in some viewers but not others, or errors only when printing, since inconsistent viewer behavior is a classic symptom of index corruption rather than genuinely missing content.
Next steps after a repair
Once a file opens reliably again, it's a good moment to also run Compress if it's bulkier than it should be, or Merge it back together with related documents — a freshly rebuilt file is a cleaner starting point for anything downstream than the damaged original was.