Alt text
Text description of an image for accessibility and SEO purposes.
What is Alt text?
Alt text (alternative text) is a text description added to images via the alt attribute in HTML. It serves two primary purposes: accessibility (screen readers read alt text to visually impaired users) and SEO (search engines use alt text to understand image content).
Good alt text describes the image content and context clearly and concisely. It should be useful to someone who cannot see the image.
Why Alt text matters
Alt text is essential for web accessibility and legal compliance. For SEO, it helps images rank in Google Image Search and provides additional keyword context for the page. Missing alt text represents a missed optimization opportunity.
How to implement
Describe the image content accurately
Keep it concise (under 125 characters)
Include relevant keywords naturally
Don't start with "image of" or "picture of"
Use empty alt="" for decorative images
Consider context within the page
Code example
<!-- Good alt text -->
<img src="/chart.png" alt="Bar chart showing organic traffic growth of 150% over 6 months">
<!-- Decorative image - empty alt -->
<img src="/decoration.svg" alt="">
<!-- Bad - keyword stuffing -->
<img src="/tool.png" alt="SEO tool SEO checker SEO audit free SEO">Common mistakes to avoid
- Leaving alt text empty on meaningful images
- Keyword stuffing in alt text
- Writing overly long descriptions
- Using the same alt text for multiple images
Examples
Good: 'SilverGecko SEO audit results showing 40 checks passed'
Bad: 'image123.jpg'
Bad: 'SEO audit tool free SEO checker website analyzer best SEO'
Frequently asked questions
Meaningful images should have descriptive alt text. Decorative images (purely visual) should use empty alt="" to be skipped by screen readers.
Keep it under 125 characters. Screen readers may cut off longer text. Be concise while accurately describing the image.