To add alt text on Twitter, upload an image to your post, tap the +ALT button on the image, type your description and tap Done. An ALT badge then shows on the posted image, and anyone can tap it to read your description. X gives you up to 1,000 characters per image, and you can add a separate description to every image in a post.
X calls alt text "image descriptions", and its help pages are unusually detailed about them. Here are the steps for phone and desktop, the setting that reminds you before you post, and X's own advice on what makes a description useful rather than a box ticked.
Why alt text matters on X
X says image descriptions make the platform accessible to people who are blind, have low vision or use assistive technology, and they also help people in low-bandwidth areas and anyone who wants more context. Without one, readers won't know what your image shows or why it matters, and X says that stops people engaging with your post. Like posts, descriptions must follow the X Rules.
How to add alt text to a post
- Start a post and upload your image.
- Tap the +ALT button on the image. ALT is short for alternative text, the technical name for an image description.
- Type your description in the text box. The character count shows in the corner.
- Tap Done. An ALT badge appears on the image, and the + sign disappears now the description is added.
- Post as normal. The ALT badge shows on the image in the posted post.
Adding several images? On iOS they appear in a horizontal scroll: tap the +ALT badge on each one. You can edit a description any time before you post by tapping it again. Once it's live, anyone who taps the ALT badge sees the description slide up from the bottom of the screen.
How X alt text differs from other sites
X's own guide makes a point worth knowing: image descriptions on X work differently from many other places. There's a 1,000-character limit, the description is the only guaranteed place to describe an image, and everyone can read it, not only people using a screen reader. So it's worth writing for all your readers. In X's espresso example, a clear description of a mug, its saucer and the table it sits on used 178 of the 1,000 characters available, which shows how much room you have for a little context.
Alt text limits on X
| Rule | X's answer |
|---|---|
| Character limit | 1,000 per image |
| Images per post | A description for each image you add |
| Videos | Image descriptions can't be added to videos |
| Who can read it | Everyone, by tapping the ALT badge |
| Where it works | The X app on iOS and Android, and X.com |
X notes that some screen readers used to stop at 200 to 250 characters. That's no longer the case, but it still recommends keeping descriptions succinct.
Turn on the alt text reminder
If you forget, X can stop you before the post goes out. Switch it on once and it applies across all platforms:
- Select the Account menu (your profile photo at the top left).
- Select Settings and privacy.
- Select Accessibility, display, and languages.
- Select Accessibility.
- In the Media section, switch on Receive image description reminder.
Next time you try to post an image with no description, X shows a reminder. Choose Add a description to write one, or Not this time to post without it.
Adding alt text with a screen reader or keyboard
X's accessibility page covers VoiceOver on iOS and keyboard use on X.com. With VoiceOver, focus on the image in the composer and swipe up or down until you hear "Add description to photo", then double-tap. On X.com, press n to open the composer, tab to the image, press enter to open the preview and type your description, then press enter while holding command (X's VoiceOver steps) or control (its JAWS steps) to finish.
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X's tips for writing a good description
- Be concise but detailed. Say what's in the image and why it matters to the post.
- Write out text in the image. If the image contains words, include them. If there's more than 1,000 characters of text, summarise what's relevant.
- Skip "Photo of" or "Image of". Assistive technology already announces that it's an image.
- Do say if it's a screenshot. That's useful context for the reader.
- Describe, don't judge. X's example: say a person is "smiling, close-lipped into the camera", not something subjective about their face.
- Don't invent a story. Describe what the image shows, not what you imagine is about to happen.
- Use full sentences. Write naturally rather than listing features.
- For charts, maps and infographics, describe the trend or finding. Then link the source in your post for anyone who wants the detail.
If you're making the graphics too, getting the size right first saves cropping problems later; my X image size guide has the dimensions.
Alt text for a business account
For brands, alt text is part of being accessible everywhere you publish, not only on X. If you're reviewing your website at the same time, my guide to web accessibility covers the basics. On X, the simple habit is to switch on the reminder, then write one or two plain sentences for every image: what it shows, any words in it, and why you posted it.
My verdict
Alt text on X takes seconds and the reminder setting means you'll never forget it. Switch the reminder on today, write what you'd say if you were describing the image to someone on the phone, and always type out any text in the graphic. Otherwise the words in your graphic are lost to anyone who can't see it.
Frequently asked questions
How do I add alt text on Twitter?
Upload an image to your post, tap the +ALT button on it, type your description and tap Done. An ALT badge appears on the image when you post.
What's the alt text character limit on X?
X allows up to 1,000 characters per image description.
Can you add alt text to videos on X?
No. X says image descriptions can't be added to videos.
How do I get X to remind me to add alt text?
Go to Settings and privacy, then Accessibility, display, and languages, then Accessibility, and switch on Receive image description reminder in the Media section.
