How to add alt text on Twitter

Alt text is the written description that travels with an image for people who cannot see it. On X you add it in the composer before you post, on the web and in the app. Quote a character cap only after Help states one. Write what is in the picture, not a caption that tries to sell the post.

What is alt text on X, and who is it for?

Alt text is the written description that travels with an image for people who cannot see it. On X you add it in the composer before you post. Write what is in the picture, not a caption that tries to sell the post. Alt text is not described as changing how the image looks in the feed.

Live help.x.com returned 403 Forbidden on 10 November 2026, America/Los_Angeles. A 13 October 2026 Wayback Machine snapshot of How to make images accessible for people was readable on that same check. It says that when you post photos on the iOS or Android app, or on x.com, "you have the option to compose a description of the images so the content is accessible to more people, including those who are blind or low-vision." It also says: "Good image descriptions are concise and descriptive, helping people understand what's happening in an image." That snapshot needs a re-read on publish day.

A search on 10 November 2026, America/Los_Angeles, treated Elgin Community College, Accessibility on X (Twitter) as the current number-one result. Elgin's page is a campus how-to for adding a description in the browser and the app. This page is the public X how-to, and it points photo-size, compression, and EXIF questions to their own answers instead of retaking them.

How do you add alt text before you post?

On X you add alt text in the composer after you attach an image, on the web and in the app. This guide will record the current control labels when you check for web and iPhone. Quote a character cap only after Help states one. If Help is silent, no number is assumed.

This page did not run a logged-in composer check on 10 November 2026, America/Los_Angeles. The 13 October 2026 Help snapshot describes the iOS path as attaching a photo, then tapping the +Alt button on the image to insert descriptive text, then tapping Done. It says you can add a description to each image in a post, and it notes: "Image descriptions cannot be added to videos." On x.com, it describes opening the thumbnail preview on the image you added and typing the description there.

The same snapshot states a limit: "The limit is 1000 characters." That number is Help's, dated to that snapshot, not a figure invented for this page. Re-check current Help on publish day before you treat 1000 as still current.

Elgin's campus page, checked the same day, reports an "Add description" control below the image in the browser, and a "+ALT" button on the image in the mobile app. Treat those browser labels as Elgin's reported UI if they differ from what you see.

Can you add or edit alt text after you post?

Whether you can add or edit alt text after a post is live is a UI and Help fact. This guide will check the post menu when you check, and date the result. If no edit path appears, none is assumed. If Help describes a later edit, quote that sentence and date it.

The 13 October 2026 snapshot describes editing the description "prior to posting the post." It does not describe an after-publish edit path. This page did not open a live post menu on 10 November 2026, so no after-publish path is assumed. If your post menu later shows an edit control, date that label yourself.

How should you write the description?

Write what a person would need to know if they could not see the image: the subject, the relevant text in the picture, and anything the post depends on. Do not stuff keywords, and do not write a second caption that tries to sell. A short before-and-after instruction is enough; do not add a customer story.

This before-and-after is instruction, not a customer story. A fictional illustration, labeled as such: if the image is a terminal window showing a failed deploy, write that the screenshot shows a terminal with a failed deploy and the error line the post is about. Do not write "best AI deploy tool growth hack screenshot." Do not add a founder who credits alt text for reach.

Does alt text change how the image looks in the feed?

Alt text does not change how the image looks in the public feed for people who can see it. It travels with the image for assistive technology and for anyone who opens the description. Photo size, compression, and EXIF stripping belong on their own pages, not here.

The 13 October 2026 Help snapshot says: "Once posted, the description applied to the image won't be visible but visually impaired people will have access to the description via their assistive technology (e.g., screen readers and braille displays)." That is the feed-appearance answer quoted here. stand on until Help is re-read.

For what happens to the file itself, see Does X compress photos? and Should you remove EXIF before posting?. Photo dimensions belong on a planned size-limits answer, which is a separate guide.

Evenpost is an app for X (Twitter) for solo founders. You and your agent draft, you approve each post in the Evenpost app, and it posts with natural spacing, or right away if you choose Post now. Updates: @evenpost. A local agent can attach a file you already have. A hosted connection cannot read a file on your computer, so you add the image in the app. The product does not write alt text, and it does not invent an alt-text field for the agent.

If you needed image dimensions or compression behavior, those live on separate photo pages. Write the description for a person who cannot see the picture.

Re-read this page when accessibility or photo Help changes, or when the composer alt-text control or any official character cap changes on web or iPhone. Help.x.com returned 403 on 10 November 2026, America/Los_Angeles, so the snapshot quoted above needs a re-read on publish day.

FAQ

Where is the alt text field on X?

In the composer, after you attach an image. The 13 October 2026 Help snapshot describes a +Alt button on iOS and a thumbnail preview on x.com. Elgin's campus page reports "Add description" under the image in the browser. Confirm the label you see today.

Is there a character limit for alt text?

The 13 October 2026 Help snapshot says the limit is 1000 characters. Live Help returned 403 on 10 November 2026, so re-check that number on publish day. This guide does not invent a different cap.

Can I add alt text on iPhone?

Yes, according to the same Help snapshot, by attaching a photo and tapping the +Alt button. This page did not open the iPhone composer on 10 November 2026, so confirm the control in your app.

Should I stuff keywords into alt text?

No. Write what a person would need to know if they could not see the image. Do not treat the description as a second caption or a keyword list.

Does Evenpost write alt text for me?

No. Evenpost does not invent alt text, and it does not offer an agent argument for writing it. A local agent can attach a file you already have. A hosted connection adds the image in the Evenpost app. You still write the description.