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Alt Text

Alt text (short for alternative text) is a written description of an image, stored in the alt attribute of an HTML <img> tag. When an image fails to load, screen readers read this text aloud to v...

Alt Text

Alt text (short for alternative text) is a written description of an image, stored in the alt attribute of an HTML <img> tag. When an image fails to load, screen readers read this text aloud to visually impaired users, and search engines use it to understand what the image depicts.

Answer capsule: Alt text is the HTML attribute that describes what an image shows. It serves two jobs simultaneously: it makes images accessible to screen readers used by visually impaired visitors, and it tells Google’s crawlers what the image contains, which affects image search rankings and on-page relevance signals.

Why Alt Text Matters for WordPress Sites

Every image on your WordPress site that lacks alt text is invisible to search engines and inaccessible to assistive technology users. The WebAIM Screen Reader User Survey consistently shows that missing or poor alt text is one of the top accessibility barriers on the web. On client sites we manage, images with descriptive alt text consistently appear in Google Image Search within 2–3 weeks of publishing—images without it rarely surface.

Google’s image search index processes alt attributes as primary signals for image ranking. A product photo labeled IMG_4892.jpg with no alt text competes poorly against a competitor’s image described as navy blue women's running shoes size 8.

How Alt Text Looks in HTML

<img src="wordpress-dashboard.png" alt="WordPress admin dashboard showing the Posts menu open" />

An empty alt="" attribute is correct for purely decorative images—it tells screen readers to skip the element entirely. Omitting the alt attribute altogether is an error; screen readers will read the filename instead, which is meaningless noise.

How to Add Alt Text in WordPress

In the block editor (Gutenberg), click any image block and look for the Alt Text field in the right sidebar under Block settings. In the Media Library, open any image and fill in the Alternative Text field—this value pre-populates when you insert the image into a post.

As of WordPress 6.4, the Media Library stores alt text per-image at the attachment level. Changing it there updates the default for future insertions but does not retroactively update alt text already embedded in published posts.

We see a common mistake on client sites: editors fill in the caption field instead of the alt text field, assuming they’re the same. They aren’t—captions display visually on-page, alt text lives in the HTML attribute and is invisible to sighted users.

Writing Effective Alt Text

Describe the image content specifically, not generically. “Woman using laptop” is weak. “Small business owner reviewing WooCommerce sales report on MacBook” gives Google and screen reader users accurate context.

Keep alt text under 125 characters—most screen readers truncate beyond that length. Include your target keyword where it fits naturally, but don’t stuff multiple keywords into a single attribute. One image, one accurate description.

Decorative images (dividers, background textures, icons used for visual spacing) get alt="" so screen readers skip them cleanly.

  • Image SEO — optimizing images for search, including file names, compression, and structured data
  • Core Web Vitals — performance metrics that include layout stability affected by images without explicit dimensions
  • Accessibility — the broader practice of making WordPress sites usable for all visitors
  • Media Library — WordPress’s built-in file manager where alt text is stored at the attachment level
  • Structured Data — schema markup that works alongside alt text to give search engines richer image context

Additional Reading

Last verified: April 2026

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