Adding alternative text descriptions, commonly known as "alt text," to images on your website is a crucial step in ensuring accessibility for users who are blind or have low vision and rely on screen readers. (https://www.allaccessible.org/best-practices-to-improve-alt-text-accessibility/) provides a textual representation of an image, allowing these users to understand the content and context of the image through their assistive technology.
When an image fails to load or cannot be displayed, the alt text also serves as a fallback description for all users, enhancing the overall user experience. Neglecting to include alt text can lead to confusion, create barriers to information access, and potentially result in (https://www.allaccessible.org/whats-the-real-risk-of-ignoring-digital-accessibility/).
In this guide, we'll explore the importance of alt text, best practices for writing effective descriptions, and step-by-step instructions for adding alt text to images on your website.
📅 October 2025 Update: AI-Powered Alt Text & WCAG 2.2 Requirements
Last updated: October 18, 2025
Alt text requirements and implementation methods have evolved significantly with WCAG 2.2 and AI-powered automation. Here's what's changed and what you need to know:
WCAG 2.2 Alt Text Requirements
WCAG 2.2 maintains the fundamental alt text requirements while clarifying implementation details:
Core Success Criteria for Alt Text:
- 1.1.1 Non-text Content (Level A) - All images must have programmatically determinable text alternatives
- 1.4.5 Images of Text (Level AA) - Avoid images of text unless customizable or essential
- 1.4.9 Images of Text (No Exception) (Level AAA) - Images of text only for decoration or where presentation is essential
2025 Compliance Requirements:
- Alt text must convey equivalent information to the image
- Decorative images must use empty alt="" (not missing alt attribute)
- Complex images require both alt text and long descriptions
- Functional images (buttons, links) must describe the action, not appearance
- Context-specific descriptions based on image purpose
AI-Powered Alt Text Generation
Artificial intelligence has revolutionized alt text creation, but human review remains essential:
How AI Alt Text Works:
- Computer Vision Analysis - AI identifies objects, people, scenes, and activities
- Context Understanding - Machine learning determines image purpose and relevance
- Natural Language Generation - AI creates human-readable descriptions
- Quality Scoring - Automated systems rate description accuracy
AllAccessible's AI Alt Text Features:
- Automatic generation for images missing alt text
- Context-aware descriptions based on surrounding content
- Bulk processing for large image libraries
- Quality validation against WCAG criteria
- Human review workflow for critical images
When to Use AI vs Manual Alt Text:
- AI suitable for: Product images, stock photos, decorative imagery
- Manual required for: Charts/graphs, screenshots with text, branded content, complex diagrams
- Hybrid approach: AI generates draft, human refines for accuracy and context
Advanced Alt Text Techniques for 2025
Empty Alt Text (alt="") - When to Use
Empty alt text is not the same as missing alt text. Use alt="" for:
<!-- Decorative image -->
<img src="decorative-border.svg" alt="" role="presentation">
<!-- Icon with adjacent text -->
<a href="/cart">
<img src="cart-icon.svg" alt="">
Shopping Cart (3 items)
</a>
<!-- Background pattern -->
<div style="background-image: url('pattern.png')">
<!-- No alt needed for CSS background images -->
</div>
Never use empty alt for:
- Images conveying information
- Functional images (links, buttons)
- Charts, graphs, or diagrams
- Logos (use company name)
Complex Image Descriptions
For charts, diagrams, and infographics, use multiple description layers:
<!-- Short alt text summary -->
<img src="sales-chart.png"
alt="2024 quarterly sales showing 25% growth"
aria-describedby="sales-details">
<!-- Detailed description -->
<div id="sales-details">
<h3>Detailed Sales Data</h3>
<p>Q1 2024: $2.5M (15% increase from Q1 2023)</p>
<p>Q2 2024: $3.1M (22% increase from Q2 2023)</p>
<p>Q3 2024: $3.8M (30% increase from Q3 2023)</p>
<p>Q4 2024: $4.2M (28% increase from Q4 2023)</p>
</div>
For extremely complex images:
- Provide data tables as HTML alternative
- Create text-based summary document
- Use
<details>element for expandable descriptions - Link to accessible PDF with full data
Functional vs Informative Images
Functional images (clickable):
<!-- WRONG: Describes appearance -->
<a href="/search">
<img src="magnifying-glass.png" alt="magnifying glass icon">
</a>
<!-- RIGHT: Describes function -->
<a href="/search">
<img src="magnifying-glass.png" alt="Search">
</a>
Informative images (convey content):
<!-- WRONG: Generic description -->
<img src="team-photo.jpg" alt="People in office">
<!-- RIGHT: Specific information -->
<img src="team-photo.jpg"
alt="AllAccessible engineering team celebrating product launch">
Testing Alt Text Quality (2025 Methods)
Automated Testing Tools:
- WAVE (WebAIM) - Detects missing alt text and empty descriptions
- axe DevTools - Validates alt text against WCAG 2.2 criteria
- AllAccessible Scanner - AI-powered quality scoring for alt text
- Lighthouse - Google's accessibility audit tool
Manual Testing Checklist:
- Turn off images in browser - does alt text convey information?
- Use screen reader (NVDA/JAWS) - is alt text clear in context?
- Review character count - is description concise (under 125 chars)?
- Check for redundancy - does surrounding text already describe image?
- Verify context - does alt text make sense without seeing image?
Screen Reader Testing:
# Windows - NVDA (free)
# Navigate to image, listen to alt text announcement
# Mac - VoiceOver (built-in)
# Cmd+F5 to enable, navigate to images
# Test questions:
# 1. Does the description make sense?
# 2. Is information conveyed equivalent to visual?
# 3. Are decorative images properly ignored?
Common Alt Text Mistakes to Avoid (2025)
1. Redundant Phrases
<!-- WRONG -->
<img src="sunset.jpg" alt="Image of a sunset over the ocean">
<!-- RIGHT -->
<img src="sunset.jpg" alt="Sunset over the ocean">
2. Keyword Stuffing for SEO
<!-- WRONG - Keyword spam -->
<img src="widget.jpg"
alt="Best accessibility widget tool software solution for websites">
<!-- RIGHT - Descriptive and natural -->
<img src="widget.jpg" alt="AllAccessible widget configuration dashboard">
3. Missing Context
<!-- WRONG - Too vague -->
<img src="chart.png" alt="Chart">
<!-- RIGHT - Provides data summary -->
<img src="chart.png" alt="User engagement increased 45% after accessibility improvements">
4. File Names as Alt Text
<!-- WRONG -->
<img src="IMG_2048.jpg" alt="IMG_2048.jpg">
<!-- RIGHT -->
<img src="IMG_2048.jpg" alt="Customer service representative assisting user via chat">
5. Overly Long Descriptions
<!-- WRONG - Too detailed in alt -->
<img src="office.jpg"
alt="A modern office space with white walls, gray carpeting,
eight desks arranged in two rows, each with a computer monitor,
keyboard, and mouse, overhead LED lighting, and a window on
the north wall showing a view of downtown buildings">
<!-- RIGHT - Concise summary -->
<img src="office.jpg" alt="Modern open-plan office workspace"
aria-describedby="office-details">
<!-- Extended description if needed -->
<p id="office-details" class="sr-only">
Eight workstations with computers, LED lighting, city view
</p>
Platform-Specific Implementation (2025)
WordPress Alt Text
// Add alt text during image upload via Media Library
// Or use this code in templates:
<?php
$image_id = get_post_thumbnail_id();
$alt_text = get_post_meta($image_id, '_wp_attachment_image_alt', true);
if (empty($alt_text)) {
// Fallback to image title or generate with AI
$alt_text = get_the_title($image_id);
}
echo '<img src="' . wp_get_attachment_url($image_id) . '"
alt="' . esc_attr($alt_text) . '">';
?>
WordPress AI Alt Text Plugins:
- AllAccessible Widget (automatic alt text generation)
- ImageSEO (AI-powered descriptions)
- Accessibility Checker (alt text validation)
Shopify Alt Text
<!-- Liquid template example -->
{% if product.featured_image.alt != blank %}
{{ product.featured_image | img_tag: product.featured_image.alt }}
{% else %}
{{ product.featured_image | img_tag: product.title }}
{% endif %}
Shopify Apps for Alt Text:
- AllAccessible Shopify App (AI automation)
- SEO Image Optimizer (bulk alt text)
React/Next.js Alt Text
// Modern React implementation
import Image from 'next/image';
function ProductImage({ product }) {
const altText = product.imageAlt ||
`${product.name} - ${product.category}`;
return (
<Image
src={product.imageSrc}
alt={altText}
width={500}
height={500}
loading="lazy"
/>
);
}
European Accessibility Act (EAA) Alt Text Requirements
The European Accessibility Act became enforceable June 28, 2025. For businesses serving EU customers:
EAA Alt Text Requirements:
- All images must have meaningful text alternatives
- Alternative formats required for complex visual information
- Multi-language alt text for international content
- Documentation of alt text processes and quality assurance
Compliance Checklist:
- All images have appropriate alt text
- Empty alt="" used only for decorative images
- Complex images have extended descriptions
- Alt text available in all supported languages
- Regular audits of alt text quality
How AllAccessible Automates Alt Text (2025)
Our platform uses advanced AI to solve the alt text challenge:
Automatic Alt Text Generation:
- Image Analysis - Computer vision identifies image content
- Context Detection - Surrounding HTML/text analyzed for relevance
- Quality Validation - AI scores description against WCAG criteria
- Human Review Queue - Flagged images sent for manual review
- Continuous Learning - System improves from user feedback
Implementation Process:
// AllAccessible automatically scans for images
// Generates alt text for missing descriptions
// Example output:
<img src="product-laptop.jpg"
alt="Silver laptop computer on wooden desk"
data-aa-generated="true"
data-aa-confidence="0.94">
Features:
- Bulk processing of image libraries
- Real-time generation for new uploads
- Quality confidence scoring
- Manual override capability
- Multi-language support
Get your free alt text audit to see how many images on your site need descriptions.
Why Alt Text Matters
- ** Accessibility and Inclusivity**
Providing alt text ensures that users with visual impairments can access and comprehend the content of your website, (https://www.allaccessible.org/diversity-equity-and-inclusion-starts-with-accessibility/). This aligns with accessibility guidelines and legal requirements, such as the Americans with Disabilities Act (ADA) and the (https://www.w3.org/TR/WCAG21/).
- ** Search Engine Optimization (SEO)**
Search engines cannot "see" images the way humans do, but they can read and understand alt text. (https://www.allaccessible.org/how-website-accessibility-affects-seo/) by providing contextual information to search engine crawlers, potentially increasing your visibility in search results.
- ** User Experience**
Alt text enhances the user experience for all visitors, not just those with visual impairments. When an image fails to load or display correctly, the alt text serves as a helpful description, ensuring that users can still understand the intended content.
Best Practices for Writing Effective Alt Text
- ** Be Descriptive and Concise**
Alt text should accurately and concisely describe the image's content and context. Avoid overly lengthy descriptions or redundant information, as screen readers may truncate or skip long alt text.
- ** Focus on Essential Information**
Prioritize the most important and relevant aspects of the image in your alt text. Consider the purpose of the image and the context in which it appears on your website.
- ** Avoid Redundancy**
If the image is accompanied by text that adequately describes its content, the alt text can be brief or even omitted, as screen readers will read both the alt text and the surrounding text.
- ** Use Appropriate Language**
Use clear, simple language and avoid technical jargon or complex terminology unless necessary. Remember that alt text should be understandable to a wide range of users.
- ** Indicate Image Type (if relevant)**
In some cases, it may be helpful to indicate the type of image (e.g., chart, diagram, illustration) in the alt text for better context.
Adding Alt Text to Images: Step-by-Step Guide
Now that you understand the importance of alt text and best practices for writing effective descriptions, let's dive into how to add alt text to images on your website.
- ** HTML
<img>Tag**
The most common way to add alt text is through the alt attribute in the HTML <img> tag. Here's an example:
"`html
<img src="example.jpg" alt="A beautiful sunset over the ocean" />
"`
In this example, the alt attribute contains the alt text description: "A beautiful sunset over the ocean."
- ** Content Management Systems (CMS)**
If you're using a Content Management System (CMS) like (https://wordpress.org/), (https://www.drupal.org/), or (https://www.joomla.org/), you can typically add alt text through the image upload or media management interface. The exact process may vary depending on your CMS, but most will have a dedicated field or option for entering alt text.
For example, in WordPress, when you upload an image to the media library, you'll see a field labeled "Alt Text" where you can enter your description.
- ** Image Editors and Online Tools**
Many image editing software and (https://www.allaccessible.org/) provide options to add or edit alt text metadata directly within the image file. This can be useful if you need to batch-process multiple images or if you're working with images outside the context of a website.
For example, Adobe Photoshop and other Adobe Creative Cloud applications allow you to add alt text to images using the "File Info" or "Metadata" panel. Online tools like TinyPNG or Squoosh also offer options to add or modify alt text during image optimization or conversion.
- ** Automated Alt Text Generation**
Some platforms and services offer automated alt text generation using machine learning and computer vision techniques. While these tools can be helpful in providing initial descriptions, it's essential to review and refine the generated alt text to ensure accuracy and relevance.
For example, services like (https://www.allaccessible.org/) can analyze images and generate alt text descriptions automatically.
Ongoing Maintenance and Testing
Adding alt text to your website's images is an ongoing process, as you'll need to ensure that new images are properly described and existing alt text is updated when necessary. Regularly auditing your website for missing or inadequate alt text is crucial for maintaining accessibility and staying compliant with guidelines.
Additionally, it's recommended to (https://www.allaccessible.org/aac-audit/) using screen readers or other assistive technologies to ensure that the alt text is being presented correctly and providing the intended user experience.
Incorporating alt text into your website's images is a fundamental step in ensuring accessibility and creating an inclusive digital experience for all users, including those with visual impairments. By following best practices and implementing the steps outlined in this guide, you can enhance your website's usability, improve search engine optimization, and demonstrate a commitment to accessibility and inclusivity.
Remember, providing alt text is not just a technical requirement – it's a way to ensure equal access to information and remove barriers for users with disabilities. Prioritizing accessibility not only benefits your users but also positions your website as a leader in inclusive design and promotes a more equitable online experience for everyone.