Image Alt Text

Why It Matters

• It is the voice of your images for people who cannot see them. Screen reader users rely entirely on alt text to understand what an image conveys. Without it, they miss information that sighted users take for granted.
• It helps when images fail to load. Slow connections, broken URLs, or blocked resources can all prevent images from loading. When that happens, the alt text appears in the image's place, keeping the content meaningful.
• Search engines cannot see images. Crawlers read the alt text to understand what the image depicts and how it relates to the rest of the page. This influences whether your images appear in image search results.
• It improves overall page context. Well-written alt text reinforces the topic of your page. It gives crawlers additional keywords and context naturally — without any need for tricks or stuffing.

How to Write It Well

1. Describe what the image shows, not what it is. "A golden retriever catching a frisbee in a park" is useful. "Dog image" is not. Think about what information the viewer would miss if the image disappeared.
2. Keep it concise. Aim for a short sentence or phrase — usually under 125 characters. Alt text is not a paragraph. It should convey the essential information quickly and clearly.
3. Skip "image of" or "picture of." Screen readers already announce "image" before reading the alt text. Starting with "image of" is redundant. Just dive straight into the description.
4. Use empty alt for decorative images. If an image is purely decorative — a background pattern, an ornamental divider, a spacer — use alt="". This tells screen readers to skip it entirely rather than announcing it.
5. Match the context. The same image might need different alt text depending on where it appears. A photo of a laptop on a tech review page might read "laptop showing benchmark results," while the same photo on a lifestyle page might read "working from a coffee shop."

Common Mistakes

• Keyword stuffing the alt text. Writing "best cheap running shoes buy running shoes online running shoes sale" as alt text helps no one. It annoys screen reader users and search engines can see right through it.
• Leaving the alt attribute out entirely. No alt attribute at all is worse than an empty one. Screen readers may announce the filename instead, leaving users with "DSC00472.jpg" — completely meaningless.
• Using the filename as alt text. "hero-banner-final-v2.jpg" is not a description. Always write actual human-readable descriptions that convey the image's content.
• Writing the same alt text for every image. If you have a gallery with ten product photos, each one should have a unique description. Identical alt text across multiple images suggests you are not actually describing what each image shows.