What is alt text and why is it important?

Alt text (alternative text) is a written description of an image that appears when the image fails to load and is read by screen readers for visually impaired users. It's important for web accessibility and SEO as search engines use it to understand image content.

How do I check if my images have alt text?

You can check alt text using browser developer tools (right-click image → Inspect), view page source (Ctrl+U), use accessibility browser extensions like WAVE, or use our free alt text checker tool above.

Should decorative images have alt text?

Decorative images that don't add meaningful content should have empty alt text (alt="") so screen readers will skip them. This prevents unnecessary clutter for users with disabilities.

Can alt text improve my website's SEO?

Yes, alt text helps search engines understand your images and can improve your website's ranking in image search results. It's also required for WCAG accessibility compliance, which search engines consider as a ranking factor.

How to check if an Image has Alt Text

Q: What makes good alt text?

Good alt text is descriptive, concise (under 125 characters), contextual to the surrounding content, and avoids redundant phrases like 'image of' or 'picture of'. It should convey the meaning and purpose of the image.

Alt text (alternative text) is a crucial element for web accessibility and SEO. It provides a text description of images for screen readers and appears when images fail to load. But how do you check if your website images have proper alt text? Let's explore the different methods and best practices.

What is Alt Text and why it matters

Alt text serves multiple purposes:

Accessibility: Screen readers use alt text to describe images to visually impaired users
SEO: Search engines use alt text to understand image content
User Experience: Alt text displays when images fail to load

Quick Methods to Check Alt Text

1. Browser Developer Tools

The fastest way to check alt text is using your browser's developer tools:

Right-click on any image
Select "Inspect" or "Inspect Element"

Look for the alt attribute in the HTML:

<img src="image.jpg" alt="Description of the image">

2. View page source

You can also check the page source:

Ctrl+U (Windows) or Cmd+U (Mac)
Search for <img tags and check for alt attributes

3. Browser Extensions

Several browser extensions can highlight missing alt text:

WAVE Web Accessibility Evaluator
axe DevTools
Accessibility Insights

What makes good Alt Text

Not all alt text is created equal. Here's what makes alt text effective:

✅ Good Alt Text Examples:

Descriptive: "Golden retriever playing fetch in a park"
Concise: Under 125 characters when possible
Context-aware: Describes the image's purpose in relation to surrounding content
Informative: Conveys the meaning, not just appearance

❌ Poor Alt Text examples:

Too vague: "image" or "photo"
Redundant: "Image of..." or "Picture of..."
Too long: Overly detailed descriptions
Missing context: Generic descriptions that don't relate to content

Common Alt Text scenarios

Decorative Images

Images used purely for decoration should have empty alt text:

<img src="decorative-border.png" alt="">

Functional Images

Images that serve as buttons or links need descriptive alt text:

<img src="search-icon.png" alt="Search">

Complex Images

Charts, graphs, and infographics need detailed descriptions:

<img src="sales-chart.png" alt="Sales increased 25% from Q1 to Q2 2024">

Images with Text

If images contain text, include that text in the alt attribute:

<img src="welcome-banner.png" alt="Welcome to Our Website">

Automated Alt Text checking

For comprehensive analysis across your entire website, automated tools are invaluable. They can:

Scan multiple pages simultaneously
Identify missing alt text
Evaluate quality of existing alt text
Generate reports for easy review

Best practices for Alt Text

Be specific and descriptive - Focus on what's important about the image
Keep it concise - Aim for 125 characters or less
Consider context - How does the image relate to surrounding content?
Avoid redundancy - Don't repeat information already in the text
Use empty alt for decorative images - Use alt="" for purely decorative elements
Test with screen readers - Use tools like NVDA or JAWS to test

Technical Implementation

HTML Implementation

<!-- Good examples -->
<img src="team-photo.jpg" alt="Marketing team of 5 people in conference room">
<img src="logo.png" alt="Company Logo">
<img src="decorative-line.svg" alt="">

<!-- Poor examples -->
<img src="team-photo.jpg" alt="image">
<img src="team-photo.jpg"> <!-- Missing alt attribute -->

Responsive Images

Don't forget alt text for responsive images:

<picture>
  <source media="(min-width: 800px)" srcset="large-image.jpg">
  <img src="small-image.jpg" alt="Detailed description works for all sizes">
</picture>

Testing Your Alt Text

Regular testing ensures your alt text remains effective:

Manual review - Periodically check your most important pages
Automated scanning - Use tools to check your entire website
User testing - Get feedback from users who rely on screen readers
Screen reader testing - Test your content with actual screen readers

Common Mistakes to Avoid

Leaving alt text empty when it shouldn't be
Using "image" or "photo" as alt text
Making alt text too long or unnecessarily detailed
Repeating filename as alt text
Forgetting context - not considering how the image relates to the content

Conclusion

Checking and optimizing alt text is essential for creating accessible, SEO-friendly websites. Regular auditing helps ensure all users can access your content effectively. Whether you use manual methods or automated tools, the key is consistency and attention to quality.

Remember: good alt text benefits everyone - not just users with disabilities. It improves your website's SEO, user experience, and overall quality.