Check and repair a PDF
Diagnose the structure of a PDF (syntax errors, encryption, version) and get a rewritten copy when possible.
Processed in your browserFree
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About this tool
A PDF that will not open or displays badly? This tool checks its structure with qpdf: version, encryption, syntax and stream errors. When the file is still readable despite warnings, a rewritten copy with clean tables is offered. The tool states clearly what it detects and what it cannot repair.
How to use this tool
- 1Drop the PDF to analyze.
- 2Read the diagnosis: version, encryption, warnings and errors.
- 3If a repaired copy is offered, download it and check it.
Limits to know
- The repair rebuilds the cross-reference tables and malformed objects; it does not recreate missing or truncated content.
- A file whose header or trailer is missing may be unrecoverable.
- An encrypted document must be unlocked for a full analysis.
- Accepted formats
- Maximum size
- 100 MB
Privacy and file processing
Encryption is handled by qpdf (WebAssembly) directly in your browser: neither the file nor the password is ever transmitted.
Read our privacy policyFrequently asked questions
It rewrites the file, rebuilding the cross-reference tables and malformed objects (missing end of file, wrong offsets). It cannot recreate missing or truncated content: a cut-off file stays unreadable.
A full analysis requires opening the content. Unlock the document with its password first ("Unlock a PDF"), then run the check again.