All PDF tools
FREE TOOL · NO UPLOAD · NO SIGNUP

Repair a PDF that will not open cleanly, right in your browser

Got a PDF that throws an error, opens blank, or will not load in your usual viewer? Drop it here. This tool reads the file in a forgiving way, skips the broken bookkeeping that trips up strict readers, and rewrites a clean PDF structure you can download. Everything happens in your browser, your file is never uploaded to a server, so it is safe for confidential drawings and NDA work. No signup, no email, no watermark. It fixes many structural and cross-reference (index) problems. It cannot rebuild a file that was cut off mid-download or is missing its actual page data.

Drop your broken PDF here
or click to browse, a PDF that errors out or opens blank
Your file never leaves your browser. The repair runs entirely on your device.

Frequently Asked Questions

Does my PDF get uploaded anywhere?
No. The repair runs entirely in your browser on your own device. Your file is never sent to a server, we never see it, and nothing is stored. That makes this safe for confidential construction drawings, NDA documents, and client files, unlike repair tools that upload your PDF to fix it in the cloud.
What kinds of problems does this actually fix?
It targets the structural bookkeeping inside a PDF: a damaged or out-of-date cross-reference table (the index that tells a viewer where each object lives), stray or malformed objects that strict readers reject, and a trailer that does not line up. The tool reads the file tolerantly, ignores those errors, then writes a fresh, consistent structure around the content it could recover. That is enough to make many files that error out or open blank open normally again.
Can it recover a file that was truncated or only half downloaded?
No, and no honest tool can. If the bytes for your pages were never fully written to disk (a download that stopped partway, a file copied off a failing drive, an export that crashed), that page data simply is not in the file, so there is nothing to rebuild it from. This tool fixes broken indexing and structure around content that is present. If the content itself is missing, re-export or re-download the original. If it opens but is unusably heavy, our compress tool is the better next step.
My CAD exports are huge and sometimes glitchy. What about those?
A repair is a one-off fix. The daily pain is opening and marking up a 50-200 MB+ AutoCAD, Revit or ArchiCAD export without your PDF tool freezing, lagging on scroll and zoom, or choking on a giant drawing in the first place. That is exactly what we built Ncored for, a fast desktop PDF editor for large construction drawings on Windows and Apple Silicon Mac. There is a free 14-day trial at ncored.com.