Supported in the MVP
- Standard text, vector, and image PDFs up to 50 MB and 100 pages.
- PDF 1.x files that open successfully in both qpdf and PDF.js.
- AcroForm and XFA files for lossless processing only; Strong mode is unavailable.
- PDF/A files with a review warning because conformance must be checked after rewriting.
Rejected before compression
- Password-protected or encrypted PDFs.
- Digitally signed PDFs, because rewriting would invalidate the signature.
- JavaScript, Launch, remote actions, embedded files, and PDF portfolios.
- Corrupt files, non-PDF content, empty files, or files beyond the limits above.
Security boundary: FitPDF detects selected risky structures but is not a malware scanner and does not guarantee that an input document is safe.