Let's dive into two closely related and crucial WCAG Success Criteria today: 1.4.4 Resize Text and 1.4.5 Images of Text. Both are Level AA requirements that champion the fundamental principle of perceivability, ensuring that users can adapt content to their visual needs without losing information or functionality.
These criteria are vital for a wide range of users, especially those with low vision, cognitive disabilities, or even temporary visual impairments.
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WCAG 1.4.4 Resize Text: Don't Break When Users Zoom!
The WCAG 2.1 criterion states:
"Success Criterion 1.4.4 Resize Text (Level AA)
Except for captions and images of text, text can be resized without assistive technology up to 200 percent without loss of content or functionality."
This criterion ensures that users can easily magnify text in their browser (e.g., using
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+What does this mean in practice?
- No Horizontal Scrolling (Ideally): While the criterion technically allows for horizontal scrolling, the best practice is to ensure content reflows vertically at 200% zoom (and ideally at 400% for WCAG 2.1 Level AA, though that's covered by 1.4.10 Reflow, it's often a side effect of good 1.4.4 implementation). Users shouldn't need to scroll horizontally to read text.
- Content Remains Visible: All text, buttons, links, and other interactive elements must remain visible and accessible. Nothing should disappear off-screen or become hidden.
- Functionality Preserved: All interactive elements must continue to work as expected. A button that becomes unclickable at 200% zoom fails this criterion.
- No Overlapping Content: Text and elements shouldn't overlap each other, making content unreadable or unusable.
- Using fixed-width layouts that don't adapt to text enlargement.
- Designing with absolute units (e.g., for font sizes and container widths) instead of relative units (e.g.,
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vw - Content being clipped or cut off when text is resized.
- Navigation menus or complex components breaking into unusable layouts.
- Use Relative Units: Primarily use relative units (,
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vw) for font sizes, line heights, spacing, and container widths where possible. This allows elements to scale proportionally.Code: Select all
vh - Responsive Design Principles: Employ responsive web design techniques (e.g., flexible grids, fluid images, media queries) that allow your layout to adapt to different screen sizes and zoom levels.
- Test Thoroughly: Regularly test your pages by zooming in your browser to 200% (and beyond) to ensure content reflows well and remains usable.
WCAG 1.4.5 Images of Text: Text is Best!
The WCAG 2.1 criterion states:
"Success Criterion 1.4.5 Images of Text (Level AA)
If the technologies being used can achieve the visual presentation, text is used to convey information rather than images of text except for the following:
- Customizable: The image of text can be visually customized to the user's requirements;
- Essential: A particular presentation of text is essential to the information being conveyed.
Note: Logotypes (text that is part of a logo or brand name) are considered essential."
This criterion prioritizes actual HTML text over text embedded within images. Why? Because real text is inherently more accessible.
Why is actual text better than images of text?
- Scalability: Real text can be resized by the user without loss of clarity (as per 1.4.4). Images of text become pixelated or blurry when magnified.
- Customization: Users can change text color, background color, font, and spacing to suit their needs (e.g., for dyslexia, low vision, or specific reading preferences). Images of text prevent this.
- Searchability: Real text can be searched, copied, and pasted. Images of text cannot.
- Screen Reader Compatibility: Screen readers can directly read real text. For images of text, they rely solely on the alt attribute, which might not always convey all the visual nuances.
- File Size: Text content typically results in smaller file sizes and faster page loads than images.
- Customizable: If the user can apply their own styles to the image of text (e.g., a custom font rendering that uses an image but allows style overrides). This is rare for common content.
- Essential: When the specific presentation of the text is crucial for the meaning or context.
- Logotypes: Text within a company logo or brand name (e.g., the stylized "Google" in the Google logo) is considered essential.
- Scientific Formulas/Mathematical Equations: Complex formulas where the layout and specific typography are critical to meaning, and cannot be easily rendered or styled in plain text without loss of information.
- Specific Aesthetic Requirement (Rarely): In very specific artistic contexts where the visual form of the text is the primary information, and it cannot be replicated with CSS/fonts. This exception is applied very strictly.
- Prioritize Live Text: Whenever possible, use actual HTML text, styled with CSS, instead of embedding text in images.
- Use Web Fonts: Employ web fonts to achieve desired typographic styles without resorting to images.
- For Logos: Ensure your logo (which is an image of text by definition) has appropriate alt text.
- For Exceptions: If you must use an image of text for an essential reason, ensure it has accurate and descriptive alt text.
Conclusion: Designing for Adaptability
Together, WCAG 1.4.4 and 1.4.5 reinforce the idea that digital content should be flexible and adaptable to user needs. By prioritizing live text and designing layouts that gracefully handle resizing, we empower users to consume information in a way that works best for them, fostering a truly inclusive and usable web experience.
What are your biggest challenges in implementing robust text resizing? Have you found creative solutions for displaying "essential" text (like complex formulas) accessibly? Share your thoughts and experiences below!