What Alt Text Is and Why AI Helps Create It

Alt text — short for alternative text — is a hidden description of an image that screen readers (software that reads content aloud) can read to people who are blind or have low vision. Without it, an image might as well be invisible to someone using assistive technology.

Traditionally, creating alt text meant manually typing descriptions for every single image. For someone managing hundreds of photos or documents, this became exhausting and error-prone. AI changes this by analyzing an image and generating a description automatically.

Why AI Is Better at This Than You'd Think

AI image recognition tools are trained on millions of labeled images, so they can identify objects, people, text, actions, and context within seconds. When you upload a photo of a dog playing in a park, the AI doesn't just say "dog" — it can describe the scene, the dog's breed, the activity, and relevant details that paint a complete picture for someone who can't see it.

The key is that good alt text isn't just factual — it's contextual. A decorative image needs a different description than a data chart. AI tools are increasingly smart about this distinction, especially when you give them a hint about what the image is for (like "this is a product photo" or "this is a chart showing sales trends").

The Practical Reality

Here's what matters: AI-generated alt text usually captures 80-90% of what a human would write, and it saves enormous time. You can review and edit the descriptions quickly, or use them as-is if they're good enough. For accessibility advocates with disabilities, this is genuinely liberating — it means creating accessible documents doesn't have to be an additional burden on top of everything else you're doing.

Some platforms (like Microsoft Word, Google Docs, and design tools) now have built-in AI alt text generators. Others require you to use a dedicated AI tool like Claude or Gemini. The process is always similar: upload or paste the image, let the AI analyze it, review the description, and publish.

One Important Caveat

AI alt text works best for straightforward images — photographs, product shots, simple diagrams. For complex infographics, charts with multiple data points, or images containing important text, you'll still want to add human judgment. The AI might miss subtle relationships or fail to capture nuance. But it's a fantastic starting point that beats writing from scratch.

Try this: Take a photo on your phone and paste it into Claude or Gemini. Ask "Write alt text for this image for someone using a screen reader." Compare what the AI suggests to what you'd naturally describe. You'll see both the strengths and where you might tweak it.