PDF tools
Repair PDF
Repack a PDF server-side to fix common structural issues.
Run Repair PDF online
Upload your file and run the job. Processing uses HTTPS and temporary storage; see the FAQ below for retention.
Enable JavaScript to use the interactive tool. Read the instructions, limitations and FAQs below before starting.
A corrupt PDF can be caused by an incomplete download, a failed email transfer, a storage device error, or a software bug during PDF generation. Symptoms include error messages when opening the file, blank pages, missing fonts, or content that displays incorrectly. A PDF repair tool attempts to reconstruct the document's internal structure from whatever valid data remains.
This repair tool reads the raw PDF stream and attempts to recover a valid, openable document. It can fix cross-reference table errors (which cause 'file not found' errors in some viewers), reconstruct broken object streams, and recover missing page descriptors. The success rate depends on the extent of damage — minor corruption is usually fully recoverable.
Common sources of corruption include interrupting a PDF download before completion, email attachments that were encoded/decoded incorrectly, and PDF-generating software that produced a malformed output. If you cannot open a PDF at all, running it through the repair tool should be your first step.
How to use this utility
- Open this page and upload the file you want to process.
- Choose options if shown, then run the action. Processing is designed to finish within seconds for typical files.
- Download the result immediately. Server-side jobs use temporary storage with automatic expiry.
Common use cases
- Fixing a PDF that shows 'file is damaged and cannot be repaired' when opening in Adobe Reader.
- Recovering a report PDF that was partially uploaded to a file storage system before the connection dropped.
- Repairing a PDF generated by a legacy system that produces structurally invalid output.
- Fixing a corrupt PDF email attachment that shows garbled content.
- Attempting to recover readable content from a PDF on a failing hard drive or damaged USB drive.
Tips for best results
- 1Download a fresh copy of the file from the source before attempting repair — a fresh download may resolve what appeared to be corruption.
- 2Try opening the file in multiple PDF viewers before declaring it corrupt — Foxit Reader and Google Chrome's built-in viewer sometimes open files that Adobe Reader rejects.
- 3If the repair produces a valid but incomplete PDF, check which pages are missing and request those specific pages from the issuer.
- 4Never delete the original file until you've verified the repaired version contains all expected content.
- 5If the tool cannot repair the PDF, contact the document issuer or the system that generated it for a fresh copy — they can usually regenerate it.
Frequently asked questions
- Is Konnect2Tools free?
- Yes. Public tools are free and do not require an account.
- Do you keep my files?
- Server inputs and outputs expire according to the job retention setting (two hours by default) and are removed by periodic cleanup. Download the result promptly; deletion is not immediate at download.
- Is the Repair PDF tool safe to use?
- Use HTTPS and only files you have the right to process. Server jobs temporarily store inputs and outputs until expiry and periodic cleanup. Keep an original copy.
- What types of PDF corruption can this tool fix?
- The tool fixes cross-reference table errors, broken object streams, missing page objects, and invalid header/trailer structures. It cannot recover content that was never written to the file (e.g., pages lost due to storage failure before being written).
- Can I repair a PDF that opens but shows blank pages?
- Yes — blank pages are often caused by missing or corrupt font or image resources. The repair process attempts to reconstruct these references. If the content was originally stored externally (linked, not embedded), recovery may be incomplete.
- What should I do if the repair tool cannot fix the file?
- Request the file from the issuing system or person again. If the file was generated by software you control, check the software's error log and regenerate. As a last resort, a data recovery specialist may be able to extract partial content from the raw binary.
- Will the repaired PDF look exactly like the original?
- In most cases, yes. However, if portions of the document data were genuinely missing (not just structurally malformed), those sections may appear blank or incomplete in the repaired output.
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