UlvixorRepair PDF
Upload a PDF that has trouble opening or a damaged structure, and this tool tries to rebuild it in your browser with pdf-lib. It's a best-effort repair: it re-parses and re-serializes the file's internal structure, which fixes many minor issues, but it can't recover severely corrupted or truncated documents.
How it works
- Select the damaged PDF file from your device.
- Click 'Try to repair'; pdf-lib loads the file (and retries ignoring encryption if it detects any) to re-parse its internal structure.
- If the file can be interpreted, pdf-lib fully re-serializes it, producing a clean, new version of the PDF.
- If the repair works, a notice confirms the document was rebuilt successfully.
- Download the result as repaired-document.pdf.
Use cases
- Try to open a PDF that other programs reject due to internal structural errors.
- Repair a file generated by software with minor errors before sending it to a client.
- Recover the content of a PDF that downloaded incompletely but with most of its data intact.
- Clean up a document before processing it with other tools on this site that require a well-formed PDF.
Use cases
- Try to open a PDF that other programs reject due to internal structural errors.
- Repair a file generated by software with minor errors before sending it to a client.
- Recover the content of a PDF that downloaded incompletely but with most of its data intact.
- Clean up a document before processing it with other tools on this site that require a well-formed PDF.
Common mistakes
- Expecting the tool to repair any PDF, including truncated files or ones missing parts.This is a best-effort re-serialization repair; if the file is severely damaged or missing data blocks, the tool won't be able to open it and will show an error saying it couldn't be repaired automatically.
- Not checking the result before discarding the original file.Download and open the repaired PDF to confirm the content looks as expected before discarding the original damaged file.
- Thinking the process also fixes incorrect visual content (blank pages, broken images), not just the file structure.The repair works on the PDF's internal structure (how the file is organized), not its content; if a page already looked blank or had visual errors before the structural damage, it will still look the same after repair.
Frequently asked questions
Minor structural PDF issues (internal references, malformed object tables) that prevent other programs from opening it, but not a large missing block of data.
Not reliably. If the file is missing a substantial part of its data, the tool won't be able to rebuild it and will show an error.
No. All analysis and reconstruction happen in your browser with pdf-lib.
The tool tries to load it ignoring the protection in order to repair it; if you also need to explicitly remove the password, use the PDF unlock tool.
Alternatives
Adobe Acrobat has a document repair feature, and command-line tools like qpdf --check or mutool clean are built for the same purpose. This tool is convenient for a quick, free attempt with no installation, directly from your browser, without uploading the damaged file to an external server.