How to Customise Text Size for Individual Apps on iPhone in iOS

While iOS allows users to scale typography system-wide via Dynamic Type, a uniform text size does not suit every application. Increasing text size globally to read long articles comfortably in Safari or Apple Books can cause button labels to truncate and clutter navigation menus in social media, banking, or messaging apps. To provide tailored visual ergonomics, Apple includes a dedicated per-app text sizing tool directly inside the iOS Control Centre, enabling you to enlarge or diminish fonts for specific applications independently.

Adding the Text Size Control to Control Centre

Before you can adjust typography on an app-by-app basis, the Text Size shortcut tile must be enabled within your Control Centre layout:

1. Open the Settings app on your iPhone.
2. Scroll down and tap Control Centre.
3. Scroll to the More Controls section (marked with green plus icons) and locate Text Size.
4. Tap the green plus (+) icon next to Text Size to move it into your active Included Controls list.
5. Optionally, drag the three horizontal lines next to Text Size to rearrange its position relative to your other quick toggles.

Adjusting Font Size for a Specific Application

Once the shortcut is active, you can modify typography dynamically while using any compatible application:

1. Open the specific app you wish to customise (for example, Messages, Mail, or Safari).
2. Swipe down from the top-right corner of your screen (on iPhones with Face ID) or swipe up from the bottom edge (on iPhones with Touch ID) to open Control Centre.
3. Tap the Text Size icon (depicted by two uppercase letters: “AA”).
4. At the bottom of the screen, you will see a toggle selector displaying two choices:
   • All Apps: Applies the selected font scale system-wide across all applications.
   • [Current App] Only: Restricts the font scale modification exclusively to the app currently running in the background.
5. Tap the option for [App Name] Only (for instance, Messages Only).
6. Drag the vertical slider up or down across the six default sizing increments to set your preferred reading scale.
7. Tap anywhere outside the slider card to dismiss Control Centre and return to the app; your new typography sizing applies instantly.

Managing and Resetting Per-App Sizing Overrides

If you wish to review all customized applications or revert an app to your system-wide baseline, iOS provides a central management hub:

1. Open Settings and tap Accessibility.
2. Scroll to the bottom of the Accessibility pane and select Per-App Settings.
3. Under this menu, you will see a catalogued list of every application where individual overrides are active.
4. Tap on any listed app to inspect its configured overrides, including Larger Text, Bold Text, Button Shapes, and Reduce Motion.
5. To restore the default system font size for an application, tap Larger Text within that app’s profile and choose Default.
6. To delete all custom accessibility rules for an application entirely, swipe left across the app’s name in the Per-App Settings list and tap Delete.

Enabling Larger Accessibility Sizes for Maximum Legibility

For users who require significantly larger text than the standard Control Centre increments permit, iOS supports expanded accessibility sizing:

• Navigate to Settings > Accessibility > Display & Text Size > Larger Text.
• Toggle on Larger Accessibility Sizes to unlock five additional, extreme magnification levels on the slider.
• Once enabled, these larger scales become accessible through the Control Centre slider, allowing you to maximize legibility in critical reading apps while preserving standard compact layouts across the remainder of iOS.

By leveraging per-app text sizing in combination with broader accessibility preferences, you can achieve an optimal balance between effortless readability and clean user interface density across your entire collection of iOS applications.