Open the Settings app.
Scroll down and select Control Center.
Make sure the Access Within Apps toggle is enabled. The toggle will be green when enabled.
In the Included Controls section, you’ll see items that are already available within your Control Center. Note: If you see Text Size in this section, that means it is already in your Control Center. Skip to the next section.
Scroll down to the More Controls section to see additional features available to add.
Select the green + icon next to Text Size.
Text Size will now be available when you open the Control Center on your iPhone.
Once you’ve completed these steps, you can exit Settings and move on to the next section to use this feature to adjust app text sizes.
How to Increase iPhone Font Size for Individual Apps
Now that you have access to Text Size in the Control Center on your iPhone, let’s learn how to change text size on iPhone for each app that’s hard to read.
First, open the app for which you want to change text size.
Open the Control Center by swiping down from the top-right corner of your screen. For iPhones with a Home button, swipe up from the bottom of the screen.
Select the Text Size icon to adjust font size.
If the All Apps icon is blue, select the [This App] Only icon. The name of the app will change depending on which app you’re adjusting at the time.
Use your finger to move the slider up or down to change font size for the app. The more white bars, the larger the font size.
Look at the top of the screen for a preview of the actual size of the font.
When you’re finished, touch a blank part of the screen to exit, then do so once more.
Now you know how to change text size for iPhone apps individually! Just repeat these steps while in each app to customize the text on an app-by-app basis.
