What Is Alt Text on X?
Alt text is a short written description you add to an image on X so people who cannot see it still get its meaning. Screen readers read it aloud, and anyone can tap the ALT badge on the image to read it.
X allows up to 1,000 characters per image description, according to its guide to writing image descriptions. To add one, upload your image, select +ALT or "Add description", type it and save, as shown on the how to add image descriptions page.
Example
You post a screenshot of a revenue chart. Weak alt text: "chart". Useful alt text: "Line chart of monthly revenue from January to June, rising from $2,000 to $11,500, with the biggest jump in April after the pricing change."
How to write good alt text
- Lead with the point. Say what the image shows and why it is in the post.
- Include any text in the image. Screenshots of posts, quotes and slides should have their words typed out, as X's guide advises.
- Keep it tight. X notes some older screen readers stopped at 200 to 250 characters. Short and specific is safest.
- Skip "image of". Screen readers already announce that it is an image.
Why it matters for growth
- More people can read your post. Blind and low-vision readers, people using assistive tech and people on slow connections all benefit.
- It shows care. Accessible posts build goodwill with readers who notice.
- Your text gets used. Words in alt text describe the image to readers who cannot load it.
Related terms
Frequently asked questions
Does alt text count towards my post's character limit?
No. Each image description has its own 1,000-character allowance, separate from the post text. See character limit for the post itself.
Should every image have alt text?
Yes, wherever the image carries meaning. A chart, screenshot or meme without a description is a blank space for anyone using a screen reader.
Last checked November 2026.
Check image dimensions alongside your alt text on our image sizes page, and preview the whole post with the mockup tool.