Alt text

Alt text (short for alternative text, and called an image description on X) is a written description attached to an image. Screen readers read it aloud, so a person who cannot see your chart, screenshot or slide still knows what it shows. X Help adds that descriptions also help people with low vision, people in low-bandwidth areas and anyone who wants more context.

Example

For a bar chart in a post about a year of sign-ups:

• Weak: "chart"
• Better: "Bar chart of weekly sign-ups for 2025. The bars rise from about 40 in January to about 160 in December, with the biggest jump in June."

Describe what matters for the post, not every pixel. Skip "image of": screen readers already say it is an image. If the image contains text (a quote card, a slide), include the text.

On X

X allows image descriptions of up to 1,000 characters. X Help notes that some screen readers used to stop reading after 200 to 250 characters; that is no longer the case, but it still recommends being succinct. On X, everyone can read an image's description, not only screen reader users. X's recommendations include capturing what is important, being objective, writing out the text in an image and using normal sentence case.

On LinkedIn

You can add alt text to images in feed posts and in articles: after uploading an image, click "Alt text" below it (tap "ALT" on mobile). LinkedIn says alt text is not visible to members who do not use screen readers, and that LinkedIn may add alt text automatically to images that have none. When it does so on desktop you are told; on mobile you are not, so check before posting.

Carousels and documents

For a carousel, describe each image you upload. If the carousel is a PDF document, also put its key points in the post text, so readers who cannot see the slides still get them.

In the Postopus editor you can add alt text to the images in your LinkedIn and X posts.

Sources

• X Help, How to write great image descriptions (1,000 characters and recommendations).
• LinkedIn Help, Add alternative text to images for accessibility.
• LinkedIn Help, Share photos on LinkedIn.

Last reviewed: October 24, 2026