How to Write Good Alt Text for Images on X

Good alt text tells someone who can't see your image what they would get from seeing it. Describe what matters for the post, in plain words, starting with the most important thing. For most photos that's one to three sentences. For screenshots of text, include the text itself. X allows up to 1,000 characters per image, which is plenty.

People rely on image descriptions for many reasons. Blind and low-vision readers use screen readers that speak the description aloud. Others have images turned off to save data, or are on a slow connection where pictures don't load. A description also helps when a photo is too small to make out on a phone.

Start from the reason you're posting

The same photo can need different descriptions depending on why it's there. Take a picture of a friend standing in front of a new bakery:

If the post is about your friend's new haircut, describe the haircut.
If it's about the bakery opening, describe the shop front and the sign.
If it's a joke about the queue, describe the queue.

Ask yourself what a sighted reader gets from the image that the text of your post doesn't already say. That's what the description should give.

What to include

Lead with the subject, then add detail in order of importance. Useful things to mention, when they matter:

Who or what is in the image, and what they're doing
The setting, if it adds meaning
Text that appears in the image, word for word if it's short
Colors, expressions or mood, when they're part of the point
What's funny or surprising, for memes and jokes

Write in full sentences or clear phrases. You don't need to be formal. A description can have personality, just as your post does.

What to leave out

"Image of" or "photo of." Screen readers announce images already.
Details nobody needs, like every object on a table, when the post is about the cake.
Guesses about people's identity, such as race, gender, age or disability, unless it's relevant and you know it. Describe what you see instead.
Hashtags and links. They're not part of the image.
Your post text, repeated. The description should add to it.

Examples

A photo posted with "Finally made it to the coast":

A wide sandy beach at sunset, the sky orange and pink. Two people walk away from the camera at the waterline, holding their shoes.

A screenshot of a message:

Text message from Mom: "Did you eat today? Also, how do I turn off the flashlight." Sent 7:42 a.m.

A chart:

Line chart of monthly visitors in 2026. It climbs steadily from about 2,000 in January to 9,500 in June, then levels off through September.

For charts, give the takeaway first, then the key numbers. If the data is complex, link to a table or summarize the main points in the post itself.

A meme:

Two-panel meme. Top: a cat staring at an empty food bowl, captioned "me at 2 p.m." Bottom: the same cat lying flat on the floor, captioned "me at 2:05 p.m."

Screenshots of text

Screenshots of long text are one of the hardest things for screen reader users. If you post a screenshot of an article, a document or a thread, put the text in the description. If it's longer than 1,000 characters, include the most important part and say where the full text can be found.

Better still, consider whether the text could go in the post or a thread instead of an image. Real text can be searched, translated and read by every device.

GIFs and video

X lets you add descriptions to GIFs as well as photos. Describe the action in a sentence: "A toddler sees a dog for the first time and squeals, clapping both hands." For video, captions and a clear post text help most, since a short description can't stand in for spoken words.

How to add a description on X

On the web, after attaching an image, select the option to add a description below the image, type it and save. On the iOS and Android apps, tap +ALT on the attached image, enter the description, and tap Done before you post. An ALT badge then appears on the image, and anyone can tap it to read the description.

If you use the TwitPickr tool, write the description in its alt text box while you crop the photo. The counter tracks the 1,000-character limit, and you can copy the text with one click and paste it into X.

You can turn on a reminder in X's accessibility settings that prompts you to add descriptions before posting images, which helps make it a habit.

Length: how much is enough?

Most photos need one to three sentences. A useful test is to read your description aloud. If it takes longer to listen to than it would take to glance at the photo and understand it, it's probably too long. If someone hearing it would still be confused about why the image is in the post, it's too short.

Complex images, like infographics, maps and dense screenshots, can justify longer descriptions. The 1,000-character limit is there for them.

Common mistakes

Leaving it blank. Any honest description is better than none.
Writing only "photo" or the file name.
Putting a joke or hidden comment in the alt text that changes the meaning of the post. People using screen readers should get the same post as everyone else.
Describing an image that's purely decorative in great detail. A short phrase is fine.

TwitPickr is not affiliated with X Corp. Menu names on X change from time to time; the steps above follow X's help center.

Quick answers

What is the alt text limit on X?

X allows up to 1,000 characters for each image description. Most good descriptions use far fewer, often one to three sentences.

Should I start alt text with "image of"?

No. Screen readers already tell the listener that it's an image, so "image of" or "picture of" just adds words. Start with what's in it.