A PDF you downloaded years ago, transferred between devices many times, or received via a flaky email service won't open. Adobe Reader shows "the file is damaged and could not be repaired". The content may be salvageable if the file structure is rebuilt. PDFKits Repair PDF attempts to reconstruct damaged PDF files in your browser. Free, no signup, no upload — useful when other tools have already given up.
PDFs have a strict structure: object tables (xref), cross-references, and a trailer. When any of these are corrupted (often by interrupted writes, transfer errors, or file truncation), the document becomes unopenable. Repair Tools rebuild these structures by scanning the file linearly and reconstructing references from the object data itself. Severe corruption (missing content streams, encrypted objects without keys) may be unrecoverable, but minor structural damage is often fully repairable.
Drop the corrupted file. PDFKits analyzes the structure and reports what's wrong: missing xref, broken trailer, truncated content, etc.
Click Repair. PDFKits scans the file linearly, rebuilds the cross-reference table from raw object data, validates each content stream, and reconstructs the trailer. The process takes 5-30 seconds depending on file size and corruption depth.
If repair succeeded, the rebuilt PDF downloads directly. Open it in your usual reader to verify. If repair failed (severe corruption), the tool reports which parts were unrecoverable.
An old contract or report from a deprecated storage system won't open in modern readers due to format drift. Repair often restores it to a readable state.
PDFs that got mangled by old MIME implementations or by aggressive mail-server filtering can sometimes be salvaged through structure repair.
Files partially recovered from failing drives often have structural damage. Repair gives them a second chance at being readable.
Output from old PDF generators may have minor non-compliance issues that prevent modern readers from opening them. Repair normalizes the structure.
Most PDF repair services either fail on real-world damage or charge per-document. PDFKits Repair PDF runs in your browser, free, with structural reconstruction logic suited for common damage types. Severe corruption may still defeat us, but minor structural issues are often fully recoverable.
Broken cross-reference tables, corrupted trailers, partial truncation at the file end, mismatched object IDs, and similar structural issues. Content stream corruption inside individual pages is harder — those pages may be unrecoverable but other pages may survive.
Visual content is preserved when content streams are intact. Bookmarks, annotations, and metadata may be partially lost depending on what was corrupted.
Repair works on the structure, not the encryption. If the encryption key data is corrupted, the file may be unrecoverable. If only the structure outside encryption is damaged, repair can succeed.
The tool reports which parts couldn't be reconstructed. Sometimes a partial repair (extracting just the readable pages) is possible — those pages can be extracted via Extract Pages on the repaired file.
Repair handles structural damage. If a virus has overwritten content with malicious payload, the content is gone — you may recover some pages but not the affected ones.
PDFKits outputs PDF 1.7 compliant files. Modern readers (Adobe, Preview, Chrome, Firefox) handle them. Very old readers may have version compatibility issues.