LinkedIn Carousel Specs Explained

Quick Answer Build LinkedIn carousels as a portrait PDF, roughly 1080 x 1350px, kept well under LinkedIn's upload limits, with somewhere between 5 and 12 slides. Those numbers aren't arbitrary — each one traces back to a specific technical or behavioural constraint. Knowing which constraint explains which number is more useful than memorising the spec sheet, because it tells you what to do the next time LinkedIn quietly changes one.

You exported your carousel at 1920x1080 because that felt like a normal size for a slide, uploaded it, and on your own phone the text on slide three is sliced clean off the bottom. Nothing crashed. Nothing errored. It just looks like you didn't check your own work before you hit publish.

By the end of this, you'll know the actual numbers — the dimensions, the file size ceiling, the slide count that holds up — and, more usefully, why each one exists at all. Most spec sheets just hand you a list of figures with no explanation, which means the moment LinkedIn nudges one of them, as it has before, the whole list goes stale and nobody notices until their carousel breaks.

Why Is a LinkedIn Carousel a PDF Instead of Just Photos?

Because the feature you think you're using doesn't exist. LinkedIn removed native, image-based carousel uploads for organic posts in late 2023. What replaced it — and what everyone still calls a "carousel" — is a document post: you upload a multi-page file, and LinkedIn renders each page as a swipeable slide.

LinkedIn accepts PDF, PPTX, and DOCX for this, but PDF is the one worth defaulting to. PowerPoint and Word files get reprocessed on LinkedIn's end, which means fonts can get substituted and layouts can shift depending on whose device opens them. A PDF freezes the page exactly as you built it. That's not a minor preference — it's the difference between your carousel looking the same on your screen and on a stranger's.

Why Is Portrait — Roughly 1080 x 1350 — the Size Worth Building To Now?

Most people default to a square or a landscape slide because that's what a normal presentation looks like. On a phone, that's working against you.

Vertical scrolling is the default posture of attention now — it has been for a while — and a taller slide simply occupies more of the screen as someone scrolls past it. More of the screen held longer means more time for the hook to register before a thumb decides to keep moving. That's the actual mechanism behind the recommendation, not an aesthetic preference for tall rectangles.

One distinction worth keeping straight: this portrait sizing is for organic carousels. Paid carousel ads, built inside Campaign Manager, are a separate format and still expect square 1080 x 1080 cards. Mixing the two up is a common, easy mistake.

Why Does LinkedIn Cap File Size, and What Happens If You Push Past It?

The instinct is to assume this is still about bandwidth — slow networks, expensive data, the stuff that genuinely shaped social formats a decade ago. It mostly isn't, anymore. Most of your audience has a fast connection. What a large file actually costs you now is a half-second to a few-second stall while the carousel loads on someone's phone — and that stall lands at the exact moment they're deciding whether to swipe at all.

A carousel that hesitates before the first slide even appears has already lost some of the momentum a clean hook was supposed to build. Keep the file size well under whatever ceiling LinkedIn currently states — compress images before you export, and don't treat the maximum as a target.

Why Is There a Slide Count "Sweet Spot" Instead of Just a Maximum?

LinkedIn's technical ceiling for a document post is generous — far more pages than any carousel should actually use. The practical range that holds up is much narrower, generally somewhere around 3 to 8 slides, because completion rate drops once a carousel demands more swipes than the topic earns. We've covered the structural side of that in the article 'Linkedin Carousel Post Best Practices in 2026', so we won't repeat it here — the short version is that the technical maximum and the actual sweet spot are two different numbers, and only one of them is worth designing around.

How Do You Actually Build to These Specs Without Re-Checking Every Time?

Set the dimensions once, export as PDF every time, and preview on your own phone before you publish — that's the whole discipline, and most carousel problems trace back to skipping one of those three steps.

The part that's easy to get wrong by hand is the first one: most general design tools default to square or landscape unless you set portrait manually, every single session. ReSlide builds to the right dimensions and exports straight to PDF, so the spec isn't something you have to remember at all — it's just what comes out the other end.

FAQ

Your Next Step Open your last published carousel on your own phone right now and check whether any text is cropped, oversized, or spilling past the edge of a slide. If it is, your export dimensions are the problem — not your content. You can easily paste your text in the ReSlide app and it will create a carousel you need with all the right specs instantly.