Select editable paragraph text
Foxit’s documented desktop paragraph workflow uses Edit > Edit Text, then selecting the paragraph. Its version 11 help places text formatting in the Format panel. The exact arrangement can differ between releases and platforms.
Use the font-size control for the selected editable text. Do not treat a selection made by a reading tool as proof that the paragraph is ready for editing.
Check whether the page is a scan
An image-based page may need OCR before its lettering becomes editable text. Foxit’s help describes a recognition prompt when using Edit Text on a scan.
Recognition can introduce text errors. Inspect spelling and punctuation as well as the font size when adapting recognized content.
Distinguish fields and comments
A form field, a typewriter comment and an existing page paragraph are different objects. If the control you expect is missing, identify the object before changing unrelated settings.
The fillable PDF form guide explains why field formatting can depend on the form’s configuration.
Check the resulting layout
Increasing the size can change wrapping or exceed the available text area. Save a separate copy and inspect nearby text, page breaks and alignment before handing off the result.
For another editor’s workflow, read Acrobat font editing. Use PDF font identification when you first need to establish the resource used by a document.
Your questions, answered.
Is page zoom the same as changing PDF text size?
No. Zoom changes the view; editing font size changes the selected content.
Why can a scan resist font-size editing?
Its visible letters may be image pixels rather than editable text. OCR is a separate recognition step and its output needs review.
Sources & background
Sources supporting this page’s explanations. Practical examples are our editorial suggestions.