Flatten PDF Online

The tool works on the interactive layer only. Form answers, checkboxes, dropdown choices, comments, highlights, stamps and signature widgets are drawn into the page; existing page text, images and vector graphics are left alone. Links are annotations too, living in the same layer, which is why many flatteners drop them. Here Keep links carries them over, so a table of contents or a web address in a footer still works, and Keep bookmarks leaves the outline panel intact for reviewers who jump between exhibits.

Vector flattening adds a few drawing instructions per field and removes the field objects, so the size barely moves, and a form full of scripts and hidden layers can even get slightly smaller. The Image method trades size for certainty: only visible pixels survive, which removes anything hidden under the surface, but text stops being selectable. 200 DPI is sharp on screen and on paper; 300 suits fine print. If the result must fit an upload cap, compress it afterward.

Batches are common with HR onboarding packets and tax forms, where one person fills and signs a dozen PDFs, and all twelve fit in one run. Merging the flat copies afterwards helps the recipient too: one file, with a bookmark per form, is easier to review than twelve attachments. If you are still deciding whether you need flattening at all, or whether Print to PDF would do, the guide on how to flatten a PDF compares the methods.