Adjust Text Size for Individual Apps on iOS 15

With the release of iOS 15, Apple introduced the ability to customize text size on a per-app basis rather than forcing a single, system-wide font size across the entire device. This update allows users to tailor the reading experience for individual third-party applications using two primary methods: an on-the-fly toggle directly within the Control Center and a dedicated configuration panel inside the Accessibility settings.

The Control Center "App Only" Toggle

The most immediate option added in iOS 15 is the per-app switch located inside the Control Center’s Text Size control. When viewing any third-party app that supports Dynamic Type, you can adjust the font scale exclusively for that application.

To use this feature:

  1. Open the third-party app you want to adjust.
  2. Swipe down from the top-right corner of the screen (or up from the bottom on Home button models) to access Control Center.
  3. Tap the Text Size control (the icon with a small "A" and large "A").
  4. At the bottom of the screen, tap the option labeled [App Name] Only instead of All Apps.
  5. Move the vertical slider up or down to set the desired font scale.

Once configured, the selected font size applies solely to that specific app, leaving the home screen, system menus, and other applications at their default sizes.

Enabling the Text Size Control

If the Text Size tile does not appear in your Control Center, it can be added through your system settings:

  1. Open Settings.
  2. Tap Control Center.
  3. Scroll down to More Controls and tap the green + icon next to Text Size.

Per-App Accessibility Settings

iOS 15 also introduced a dedicated Per-App Settings menu inside Accessibility. This section provides a permanent, centralized hub to configure font adjustments and visual styles for specific third-party apps without needing to open them first.

To configure text size through this menu:

  1. Open Settings and select Accessibility.
  2. Scroll to the bottom and tap Per-App Settings.
  3. Tap Add App and select the third-party application from your installed list.
  4. Tap the app's name once it appears in the list.
  5. Select Larger Text to adjust the font size slider specifically for that application.

In addition to the slider, this menu allows you to enable Bold Text on an individual app basis, providing further control over text legibility.

Third-Party App Compatibility

These adjustments work seamlessly with any third-party application that utilizes Apple’s Dynamic Type framework. While most modern iOS apps support this standard, apps that rely on hardcoded font sizes or custom rendering engines may not reflect these adjustments.