Start with an example
Say you post a bar chart of your team’s support response times. Here are three ways to describe it, from useless to useful. The numbers are made up for the example.
| Alt text | What a screen reader user gets |
|---|---|
| Image | Nothing they did not already know. |
| Chart | Slightly more, still no information. |
| Bar chart of average support response time by month, January to June. Response time drops from about two days to under one day after the new help center launched in March. | The point of the chart, which is the reason you posted it. |
The third one is longer, and that is fine. It carries the one thing the image exists to say. Length is not the goal; the point is.
Where it goes on LinkedIn
When you attach an image to a post, LinkedIn gives you an option to add alternative text before you publish. The label and its position shift a little between the mobile app and desktop, so look for it on the image editing screen. If you skip it, LinkedIn may generate a description automatically for some images. Those tend to be generic (“a person standing in front of a screen”), so writing your own is worth the extra half minute.
Most readers never see alt text. Screen readers, used by people who are blind or have low vision, read it aloud. It can also appear in place of the picture if the image fails to load.
What to write for common images
- A chart or graph: the chart type, what it measures and the trend or number that matters.
- A screenshot of a quote: the full quote and who said it.
- A slide or infographic: the headline and the main points, in order.
- An event photo: who is in it, where, and what is happening, if that is why you are posting it.
- An announcement graphic: a short description plus any text on the image, such as “Now hiring: two backend engineers.”
What to leave out
Skip “image of” and “picture of.” Screen readers already announce that it is an image. Skip keyword lists too. Alt text is for people, and stuffing it with search terms makes it worse for exactly the readers it is meant to help. Leave out decoration nobody needs, like the color of a background, unless the color carries meaning.
One test we like: if you cannot say the point of an image in a sentence or two, the image may not have a clear point yet. That is a design problem, and fixing it helps every reader.
Carousels and document posts
A document post shows a PDF page by page, and page-level descriptions may not be available. Put the main takeaway in the post text above the document as well, so nobody misses the core of what you shared. High contrast and large type on each page help everyone. You can design the pages with the free Carousel Generator, and the walkthrough on how to make a LinkedIn carousel covers layout.
Alt text is not a caption
A caption is visible to everyone and adds context: why you are sharing the chart, what you think it means. Alt text describes what is in the image. A good post often has both, and they should not repeat each other word for word. For more ways to make a post easy to read, see how to format a LinkedIn post.