What does Flatten to Image PDF not protect?
It destroys all structure, including useful structure. Text selection, form filling, accessibility features, and bookmarks are gone. File size increases for text-heavy documents. The 200-page cap exists for browser memory safety.
What this does not protect
- Text becomes non-selectable. Recipients cannot copy-paste, search, or index the text. If they need searchable text, they would need to OCR the result.
- Output file size is almost always larger than the original for text-heavy documents. A 500KB text PDF may become 3-5MB after flatten at 150 DPI.
- 200-page cap exists because each page requires ~50-100MB of RAM for canvas rendering. For longer documents, split first and flatten sections.
- Transparent elements and blend modes may render differently than in specialized PDF viewers. Always verify the output.
- It cannot fix compromised devices, accounts, or unsafe sharing channels.