Just updated to iOS 17.5 and I have what I think is a new issue: I'm looking at a note and the font is uncomfortably small.
Is there any way to change this when viewing notes already created and synced between phone and computer, without going back to the computer?
I don't remember such a problem before the update: my default notes font seemed to be just fine.
iPhone 12 mini, iOS 17
Hi, and welcome to te Apple (user-to-user) Community!
Re: "Resize font in notes app on iOS?"
Wondering if Apple Support's online article (link below) can help:
Use display & text size preferences - Apple Support
Eg says:
In settings: "Tap Accessibility > Display & Text Size.
You can find these accommodations on the Display & Text Size screen:
All the best :-)
You might want to try the other option:
Create and format notes on iPhone - Apple Support
says:
Format text
, then choose a style such as Heading, Monostyled, bold or italic font, block quote, bulleted or numbered list, and more.Tip: To choose a default style for the first line in all new notes, go to Settings 
> Notes > New Notes Start With.
There's also another discussion thread online (link below) with other suggestions:
That allows me to change the system fonts, but not to select and adjust the size of fonts immediately while within the notes.app--fonts that for whatever reason are appearing smaller than default system font.` It's mind boggling that I cannot do something so simple on such a smart device.
Resize font in notes app on iOS?
