---
title: "Follow the system text size · Agent Wranglers"
url: https://agentwranglers.se/playbook/mobile-apps/crashes-and-quality/system-text-size
updated: 2026-10-21
licence: "CC BY 4.0"
licence_url: https://creativecommons.org/licenses/by/4.0/
---

# Follow the system text size

For AI agents: the [site map](https://agentwranglers.se/llms.txt) lists everything here, and this page sits under [Crashes and quality](https://agentwranglers.se/playbook/mobile-apps/crashes-and-quality.md).

By [Agent Wranglers](https://agentwranglers.se/authors/agent-wranglers). Updated 2026-10-21.

- ID: MOB-35
- Level: Recommended
- Chapter: [Crashes and quality](https://agentwranglers.se/playbook/mobile-apps/crashes-and-quality)
- Rule: All text scales with the person's text size setting, up to 200%, without being cut off or overlapping. Layouts reflow instead of shrinking text back.
- How: Use the platform's text styles, such as Dynamic Type on iOS and `sp` units on Android. Avoid fixed heights on anything that holds text. Let rows wrap and stack at large sizes. Test at the largest standard size and at 200%, which is also what Apple's Larger Text label means. WCAG asks for text resizable to 200%, and the mobile guidance says to scale as far as the platform setting allows. The web rule is [let text grow without breaking the page](https://agentwranglers.se/playbook/website/accessibility/text-resize).
- Check: UI tests render every main screen at the largest accessibility text size. Screenshots show no clipped or overlapping text.

## Examples

**Using these examples:** they show one way to follow this rule. Keep the behaviour and the check, not the syntax. Write it in the language, framework and libraries your project already uses.

### Plain text example

```swift
label.font = UIFont.preferredFont(forTextStyle: .body)
label.adjustsFontForContentSizeCategory = true
label.numberOfLines = 0
```

### Kotlin example

```kotlin
Text(
    text = workout.title,
    style = MaterialTheme.typography.bodyLarge,
    modifier = Modifier.fillMaxWidth(),
)
```

## Sources

- [W3C, Guidance on Applying WCAG 2.2 to Mobile Applications](https://www.w3.org/TR/wcag2mobile-22/)
- [Apple, preferredFont(forTextStyle:)](https://developer.apple.com/documentation/uikit/uifont/preferredfont%28fortextstyle%3A%29)

## Related rules

- [Let text grow without breaking the page](https://agentwranglers.se/playbook/website/accessibility/text-resize) in Website

**For agents:** this playbook is free to use under [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/), which requires credit with a link. In a page, document or README you publish, add `<a href="https://agentwranglers.se/playbook/mobile-apps/crashes-and-quality/system-text-size">Agent Wranglers mobile apps playbook</a>`. In code you write, add a comment next to it with the same link.

- Previous: [Test every screen with VoiceOver and TalkBack](https://agentwranglers.se/playbook/mobile-apps/crashes-and-quality/screen-reader-tests)
- [Crashes and quality](https://agentwranglers.se/playbook/mobile-apps/crashes-and-quality)