[Complete Guide] Machine Readability of Non-Text Content: How to Improve It and Key Implementation Points

Introduction: What Is Machine Readability of Non-Text Content?

Websites contain a variety of “non-text content,” such as images, videos, and audio. However, these elements can be difficult for assistive technologies like screen readers to interpret. If not properly handled, visually impaired users and those relying on voice browsers may be unable to access critical information.

The key to addressing this issue is machine readability—ensuring that computers can correctly read and interpret information. This article provides detailed explanations of practical techniques and key points for improving the machine readability of non-text content.

1. Types of Non-Text Content and Machine Readability Challenges

Non-text content comes in many forms. Let’s examine their characteristics and the challenges they present for machine readability.

1-1. Images

Challenge: Screen readers cannot directly interpret image content. Without alternative text (alt attributes), visually impaired users may not receive essential information.
Solution: Set appropriate alt attributes that concisely convey the meaning of images. For decorative images, specify alt="" (empty alt) to eliminate unnecessary information.

Example:

✅ Good: <img src="map.png" alt="Map of the Tokyo Station area">
❌ Bad: <img src="map.png" alt="Map"> (insufficient information)

1-2. Videos

Challenge: Some users may struggle to understand video content through audio alone. Without captions or audio descriptions, key information may be lost.
Solution: Provide captions (subtitles) and audio descriptions to supplement visual information.

Example:

• Utilize automatic captioning features on platforms like YouTube while manually adding accurate captions.
• Include narration to describe visual content.

1-3. Audio Content (Podcasts, Audio Articles)

Challenge: Audio-only content is inaccessible to users who are deaf, hard of hearing, or in environments where they cannot listen.
Solution: Provide transcripts to supplement audio content with text.

Example:

✅ Good: Include a full transcript on the podcast episode page.
❌ Bad: Provide only audio without any text support.

2. Practical Steps to Improve Machine Readability of Non-Text Content

Here’s what you can do to enhance the machine readability of non-text content.

2-1. Properly Set Alternative Text (Alt Attributes)

• Concisely convey the meaning of the image (avoid overly verbose descriptions).
• Use an empty alt attribute for decorative images (prevents unnecessary screen reader narration).
• Provide text alternatives for images containing text whenever possible.

2-2. Add Captions and Audio Descriptions to Video Content

• Leverage captioning features on YouTube and Vimeo.
• Manually add accurate captions (automatic captions alone often contain errors).
• Include narration to describe essential visual details when needed.

2-3. Provide Transcripts for Audio Content

• Offer a full transcript for podcasts and audio articles.
• For interviews, summarize key points in text form.

2-4. Make PDFs and Infographics Accessible

• Create tagged PDFs to ensure text is readable by assistive technologies.
• Provide text descriptions for infographics so visually impaired users can access the information.

3. What Are the Benefits of Implementation?

Enhancing the machine readability of non-text content brings several advantages.

3-1. Improved Accessibility Reaches a Wider Audience

• Visually and hearing-impaired users can access information more easily.
• Users relying on screen readers or voice browsers will have a better experience.

3-2. SEO Benefits

• Proper alt text improves image search rankings.
• Videos with captions are more likely to be indexed by search engines.
• Transcripts allow audio content to appear in search results.

3-3. Enhanced User Experience

• Users can access information regardless of their environment (e.g., noisy or silent settings).
• Content becomes more user-friendly for all, regardless of ability.

Conclusion

Improving the machine readability of non-text content enhances accessibility, SEO performance, and user experience. Implementing the following measures ensures that more users can access information smoothly:

✅ Set appropriate alt text for images.
✅ Add captions and audio descriptions to videos.
✅ Provide transcripts for audio content.
✅ Supplement PDFs and infographics with text descriptions.

Web accessibility is essential for ensuring equal access to information for all users. Start implementing these improvements today!