Alt text for carousels: describing a sequence

Someone swipes through your ten-slide carousel one thumb-flick at a time: cover, hook, three data points, a bold quote, a CTA. A screen reader user doesn't get the flick. They get slide one, then a choice — keep going or move on — repeated ten times, with nothing to go on but whatever you typed into each slide's alt text field, if you typed anything at all.

Carousels are one of the most common formats on Instagram and LinkedIn right now, and they're also one of the easiest places for alt text to fall apart, because the habits that work for a single photo don't scale to ten of them.

A carousel is several posts wearing one post's clothes

A single image only has to carry one idea. A carousel has to carry an argument across slides — and each slide's alt text is doing two jobs at once: describing what's on that slide, and making sense as part of a sequence someone is moving through one screen at a time. Write all ten slides the same generic way ("carousel slide," "graphic," "text slide") and the sequence itself disappears — a screen reader user gets ten identical, useless lines instead of an argument.

Write the slide, not the topic

The fix is the same discipline as any alt text, applied slide by slide: describe what's actually on that specific image, not the general subject of the post. A data slide gets the takeaway, not "a chart." A quote slide gets the quote's substance, not "quote graphic."

Most screen readers already announce a carousel's position in the sequence ("item 2 of 6") as part of the platform's own interface, so you don't need to spend characters restating "slide 2 of 6" yourself — put that budget toward what's actually in the image.

Instagram gives you a field per slide. LinkedIn mostly doesn't.

On Instagram, each image in a carousel gets its own alt text field, the same as a single photo. On mobile, scroll to More Options on the final publishing screen and tap Write Alt Text; on desktop, expand the Accessibility accordion below the caption box. After it's live, you can still fix a slide: tap Edit, swipe to the slide that needs work, and tap its alt text to update it.

LinkedIn is different. Since it retired native multi-image carousels, most "LinkedIn carousels" are actually a multi-page PDF or slide deck uploaded as a document post — and there's no per-page alt text field to fill in after the fact. The accessibility of each slide comes from whatever tags and reading order were built into the source file before you exported it to PDF, not from anything you can patch in LinkedIn's editor. If a LinkedIn carousel needs to be accessible, that work has to happen in the deck, not on LinkedIn.

One rule for the whole set

Before you publish, read your slide descriptions in order, without looking at the images. If they tell a coherent, specific story — not ten variations of "image" — you're done. That's a slower check than writing alt text for one photo, but it's the only way to know the sequence actually survives being heard instead of seen.