Start with the image’s job
Alt text is a written alternative to an image. It can be read aloud by a screen reader when someone encounters the image, and it can help when the image does not load. For a creator, the goal is not to inventory every visible detail. It is to give someone who cannot see the image the information they need to follow the content.
Before writing, ask: Why did I include this image here? A photo might establish a setting, show a product feature or deliver the punch line of a joke. The same photo could need different alt text in different posts. If an article is about the design of a café menu, the menu’s layout and readable wording matter. If the menu happens to be in the background of a portrait, those details may not matter at all.
Write for that purpose. “Person holding a phone” may be enough in one context. In a tutorial about a settings screen, the relevant detail is what appears on the phone and what the reader should notice.
Describe what matters, then stop
Good alt text is specific without making the reader work through unnecessary detail. Identify the main subject and include the features that carry meaning: an action, a relationship between objects, visible text or a change the image demonstrates. “Two overlapping reply boxes obscure the original post” is more useful than “Screenshot of a social media page” when the article is about a confusing interface.
Usually, you can skip openings such as “Image of” because the image is already identified as an image. You can also leave out guesses about a person’s feelings or identity when the picture does not establish them. Describe visible evidence instead: “A speaker stands beside a slide with a blank chart” rather than “An anxious presenter struggles with bad data.”
Length depends on complexity and context, not a fixed word count. A simple icon may need only a few words; an editorial photograph may need a sentence. If your description starts becoming a paragraph, consider whether some of that information belongs in the surrounding article or a visible caption instead.
Handle text, screenshots and charts with care
When text inside an image carries the point, make that text available. A screenshot of a button might need “Button labeled ‘Save draft’ below the post preview.” A screenshot of a long conversation is harder: summarize its relevant exchange in the alt text, then provide a transcript or quote the essential lines in the article if readers need the full wording. Do not rely on tiny text in an image to deliver important instructions.
For charts, state the takeaway the image supports and name the elements needed to understand it. For example: “Line chart showing newsletter opens rising through the first three sends, then leveling off.” If exact values, labels or comparisons matter to your argument, put them in nearby text or an accessible table. Alt text can orient a reader, but it should not have to carry an entire dataset.
Memes and visual jokes need similar judgment. Describe both the setup and the detail that makes the joke work, without explaining it at length if a brief description will do. If the image’s wording is central, include it or provide it in the surrounding post.
Know when an image needs no description
Not every published image adds information. A decorative flourish, repeated background pattern or spacer may be best marked as decorative using the publishing tool’s available setting. This lets readers move past it rather than hearing a description that interrupts the page. Do not treat an image as decorative merely because it is attractive: a cover image that introduces a person, place or idea may still have a meaningful role.
Captions and alt text can work together. A caption is visible to everyone and may add context, attribution or commentary. Alt text describes what someone needs to know about the image itself. If the caption already supplies a fact, the alt text need not repeat it word for word; it can fill in the visual detail the caption assumes.
Make alt text part of your publishing routine
The easiest time to write alt text is when you choose the image, while you still remember why it belongs there. Keep a short check in your workflow: confirm the image has a purpose, write its alternative in the platform’s alt-text field, and read the surrounding text and alt text in sequence. Does the description add what is missing, or does it repeat a sentence the reader just heard?
Preview the published result when you can. Some platforms handle captions, embedded images or automatic descriptions differently, so check that your own text appears in the intended field. If a platform gives you little room for a complex image, move essential details into the visible post rather than squeezing them into an unclear phrase.
Alt text is a writing skill, not a test of perfect object recognition. A useful description reflects the point you are making, respects what the image actually shows and gives readers a way to keep moving through your story.
