How the PDF repair works
The tool loads your PDF using pdf-lib with fault-tolerant parsing, which means it ignores invalid objects and structural errors that would normally cause the file to fail. It then re-saves the file with a clean, standard structure. This can fix minor corruption such as incomplete downloads, truncated files, or cross-reference errors.
What types of damage can be fixed?
- Incomplete downloads — files cut off before fully downloading.
- Cross-reference table errors — internal PDF index corruption.
- Invalid objects — malformed internal objects that cause viewer errors.
What cannot be fixed?
Severely corrupted files where large sections of content are missing cannot be recovered. Password-encrypted files with unknown passwords cannot be repaired. Physical storage damage (bad sectors on a hard drive) is also beyond what this tool can recover.
Privacy
All processing is in your browser. No file is sent to any server.