Alt text for Facebook — and why the auto-generated version isn't enough

Facebook is unusual among social platforms: it will not leave your image undescribed. If you skip the alt text field, its computer vision system writes something anyway, and screen reader users hear it. That sounds like a solved problem. Listen to what it actually says and it stops sounding solved.

A typical automatic description is "May be an image of 3 people and text." That's the whole thing. Three people, some text, a hedge at the front because the system isn't sure.

What the automatic descriptions can and can't do

Meta's automatic alt text runs on object recognition. It's good at nouns — people, a dog, a beach, a building — and it has gotten better over the years at activities and landmarks. What it cannot do is know why you posted the image. It doesn't know the event has a deadline, that the person in the photo is your new director, or that the words on the graphic are the entire message.

There's a quieter problem too: hedged phrasing. "May be an image of" tells a listener that nobody stands behind this description. On a brand page, that's a small but real signal about how much care went into the post.

Where the field actually lives

On desktop, before you publish: click Edit in the upper-left corner of the uploaded image, choose Alternative Text in the Photo Detail window, write your description, and save. On mobile, tap the three dots in the upper-right corner of the uploaded image and choose Edit Alt Text.

Posts that are already live are fixable, which is not true everywhere. Open the image, click the three dots in the upper right, and choose Change Alt Text on desktop or Edit Alt Text on mobile. Facebook won't show you a published post's alt text in the interface, though, so there's no quick way to eyeball which of your archive is described and which is running on autopilot.

One thing worth knowing if your team schedules: as of April 2026 the alt text field is gone from Meta Business Suite entirely. Composing natively, or using a third-party scheduler that can still reach the field, is the way back to it.

What to write instead

Lead with the subject. Add the one detail that carries the message. If there are words in the image — a date, a price, a headline — read them out; that text is invisible to a screen reader otherwise. Aim for roughly 125 characters, the point past which some screen readers truncate.

Facebook sometimes suggests keeping a description under 100 characters. That's a display recommendation, not an accessibility rule, and it isn't a hard limit. If an image genuinely needs more words, use them.

The practical bar is low. Automatic alt text gives a listener a rough inventory of the frame. Eight words of your own gives them the post. On a page publishing several images a week, that gap compounds fast — and it's the cheapest gap on your whole content calendar to close.