...
Most social media alt text is useless: 'Image may contain: person, indoor.' AI image description can generate meaningful alt text automatically — here's what good alt text actually looks like.
You post a photo on Instagram. You add alt text: "Image may contain: person, standing, indoor." This is what Instagram's automatic alt text generates. It is technically accurate. It is also completely useless to a blind or low-vision user trying to understand your post. "Person standing indoor" describes approximately 40% of all photos on Instagram. It communicates nothing.
Good alt text answers one question: "If I could not see this image, what would I need to know about it?" An AI image description tool can generate detailed, meaningful descriptions automatically. But the AI describes what it sees. You need to add context — why the image matters in the context of your post. Here is how to write alt text that actually helps people.
Bad: "Image may contain: person, indoor." This is Facebook's automatic alt text. It identifies objects but conveys nothing about the scene, the action, the emotion, or the relevance. It is the result of an object detection model that was asked to label images, not describe them. It is better than nothing. It is not good enough.
Bad: "Photo." This is what most people write when they manually add alt text. It communicates zero information. It is worse than the automatic alt text. It tells the user there is an image and nothing about what is in it.
Bad: "Our new product launch event was a huge success! We are so grateful to everyone who attended." This is the caption, not the alt text. It describes the event, not the image. A blind user reading this alt text learns nothing about what is visible in the photo — who is in it, what is happening, what the scene looks like.
Good: "Three people standing behind a table with a white tablecloth, holding champagne glasses and smiling at the camera. A banner behind them reads 'Product Launch 2026.' The room is a conference hall with blue uplighting."
This description answers: who is in the image (three people), what are they doing (holding champagne, smiling, posing), what is the setting (conference hall, table with tablecloth), and what is the key visual detail (the banner text). A blind user reading this description can picture the scene. The description is not poetic. It is information-dense.
Use an AI image description tool to generate the first draft of the description. The AI identifies the objects, people, setting, and actions. Then you add the context: why is this image in the post? What does the viewer need to know that the AI cannot infer? The AI describes the pixels. You describe the meaning.
Google uses alt text to understand image content for image search. Descriptive alt text improves your chances of ranking in Google Image Search, which drives 20-30% of search traffic for many sites. The accessibility benefit and the SEO benefit align: describe the image accurately and specifically. The same alt text that helps a blind user understand your photo helps Google understand your photo. There is no conflict between accessibility and SEO. They ask for the same thing.
Decorative images — background patterns, divider lines, purely aesthetic elements — should have empty alt text (alt=""). An empty alt attribute tells screen readers to skip the image entirely. This is better than "Decorative background pattern" — which forces the user to listen to a description of something they do not need to know about. The rule: if removing the image would not change the meaning of the content, the alt text should be empty.
Generate alt text for your images at AI image description — the AI describes the pixels, you add the context, and the result is alt text that actually helps.