Alt text is a short written description of an image that screen readers read aloud. It makes your posts usable for people who are blind or have low vision, and it also gives platforms and search engines more context about what the image shows.
Good alt text describes what matters in the image in one or two plain sentences. Mention people, actions, key objects and any text in the graphic. Skip phrases like "image of" because screen readers already announce that it is an image.
Most major platforms, including Instagram, LinkedIn, X and Facebook, let you add custom alt text when you upload. If you skip it, some platforms generate an automatic description, but it is often vague or wrong.
Questions about Alt Text
How do you write good alt text?
Describe the important details in one or two concise sentences: who is in the image, what is happening and any text shown. Keep it specific and natural. Avoid starting with "image of" and avoid stuffing it with hashtags or keywords.
Does alt text help SEO or reach?
It can help. Alt text gives platforms and search engines extra information about your image, which may support discovery in search. Its main purpose is accessibility, though, so write it for people first rather than for algorithms.
Should every social media image have alt text?
Ideally, yes. Any image that carries meaning should have alt text so everyone can understand the post. Purely decorative graphics matter less, but on social media nearly every image is part of the message, so adding a description is a good habit.
