Applying WCAG 2.1 Standards to iOS Mobile Apps: A Comprehensive Guide

The Web Content Accessibility Guidelines (WCAG) is a universally recognized set of recommendations designed to make web content more accessible for individuals with disabilities. Developed by the World Wide Web Consortium (W3C), it has emerged as a vital framework for web accessibility.

But how does WCAG apply to mobile apps, specifically iOS apps? Despite its name, WCAG isn't exclusive to websites and is very applicable to mobile applications. In this post, we'll explore the application of WCAG 2.1 standards to iOS mobile apps.

  1. Understanding WCAG 2.1

WCAG 2.1 is the latest version of the guidelines, introducing new success criteria addressing mobile accessibility, people with low vision, and people with cognitive and learning disabilities. WCAG 2.1 is organized around four principles: Perceivable, Operable, Understandable, and Robust (POUR).

  1. Applying WCAG 2.1 to iOS Apps

Let's explore how these principles can be incorporated into iOS app design and development.

2.1. Perceivable

Perceivable relates to the visibility of the content and information on your app.

  • Text Alternatives: Offer text alternatives for non-text content. For example, add descriptive alt text to images and UI elements so that screen readers like VoiceOver on iOS can interpret them.
  • Time-Based Media: Provide alternatives for time-based media, like captions for videos or audio descriptions.
  • Adaptable: Create content that can be presented in different ways without losing meaning. Make sure your layout works in both portrait and landscape orientations, and elements resize correctly for different screen sizes.
  • Distinguishable: Make it easy for users to see and hear content. Ensure there's sufficient contrast between text and background colors. iOS provides Dynamic Type which allows users to specify their preferred text size across all apps that support it.

2.2. Operable

This principle refers to how users interact with your app.

  • Keyboard Accessible: All functionality should be operable via a keyboard interface. In the context of iOS, this means ensuring that all features are accessible and usable through different interaction methods, like switch control.
  • Enough Time: Provide users enough time to read and use content. If your app contains time-limited processes, ensure you provide options to turn off, adjust, or extend the time limit.
  • Seizures and Physical Reactions: Do not include design elements that could cause seizures or physical reactions. Avoid flashing or flickering content.
  • Navigable: Provide ways to help users navigate, find content, and determine where they are in the app. Use semantic markup to create a logical structure and clear headings.

2.3. Understandable

This principle relates to how easily users can comprehend the app's content and interface.

  • Readable: Make text content readable and understandable. Keep your language simple and clear. iOS supports Text Styles, which conform to the user’s selected content size, and also offer automatic adjustments for weight and letter spacing.
  • Predictable: Make web pages appear and operate in predictable ways. Maintain consistent navigation and labeling across your app.
  • Input Assistance: Help users avoid and correct mistakes. Offer validation and error recovery for forms. Make sure error messages are clear and provide guidance for correction.

2.4. Robust

This principle ensures the app's compatibility with current and future technologies.

  • Compatible: Maximize compatibility with current and future user tools. Use valid, clean, and semantic code to ensure your app works well with assistive technologies.
  1. WCAG 2.1 Compliance Tools for iOS Apps

Tools like Accessibility Inspector, part of Xcode, can be used to test the accessibility of your app. It provides a range of features to help you assess how successfully your app meets the WCAG 2.1 guidelines.


Making your iOS app accessible is not just a matter of social responsibility or compliance with regulations—it also makes good business sense, broadening your potential user base. As developers and designers, we have a role to play in making digital experiences inclusive and accessible to everyone. Use WCAG 2.1 as your roadmap to create more accessible iOS applications.