TLDR
Make each slide 1080×1350 px (4:5 portrait) and export the whole set as one multi-page PDF under 100 MB. LinkedIn accepts up to 300 pages — keep it under 12. Before uploading, open the PDF and zoom to 100%: low-resolution exports are the number-one cause of blurry carousels, and there's no fixing them after posting.
The numbers
Two of these numbers do all the work: 1080×1350 and 100 MB. The rest are boundaries you should never get near — a carousel that needs 300 pages or 100 MB has already lost its audience. Eight to ten slides at a correct page size is the whole game.
If you haven't posted one before, the mechanics are covered step by step in our guide to posting a carousel on LinkedIn — the short version is that LinkedIn has no carousel button at all. You upload a PDF through the document icon, and LinkedIn renders each page as a swipeable slide.
Your export pipeline decides the sharpness
This is the part most spec lists skip, and it's why "what size is a LinkedIn carousel" has a sneaky answer. LinkedIn doesn't ask for image dimensions anywhere. It takes your PDF and renders each page as a slide — and a PDF page is measured in points, not pixels, so "1080×1350" is really a 4:5 composition target. What actually decides sharpness is the resolution of the artwork embedded in each page (vector content scales cleanly), and that's fixed at export time — before LinkedIn ever sees it.
That's where things go wrong. Some export paths rasterise slides at print-oriented resolutions or quietly downsample images. LinkedIn then stretches that soft page across a phone screen, and the result is text with smudged edges. The design was sharp; the export wasn't.
We render carousel exports for LinkedIn every day, and this is the single most common failure mode people arrive with from other workflows — the design tool did nothing wrong, the export settings did. The fix is a ten-second check:
- Open the exported PDF in any viewer.
- Zoom to 100% and read the smallest text on a slide.
- If it's soft, re-export at full resolution from lossless sources — don't upload.
Check before posting, not after. LinkedIn doesn't let you swap the PDF on a published document post. If you spot the blur once it's live, the only fix is deleting the post — and its impressions and comments — and starting over.
Portrait vs square vs landscape
All three supported ratios work mechanically. They do not perform equally, and the reason is screen area, not algorithm magic.
- 1080×1350 (4:5 portrait) — the default. It occupies the most vertical space a LinkedIn feed allows, which matters because 70%+ of LinkedIn traffic is mobile. More screen occupied means longer dwell before the scroll decision, and dwell is the signal carousels are built to farm.
- 1080×1080 (1:1 square) — fully supported, loses roughly 30% of the vertical space portrait gets on a phone. Reasonable only when the same slides must also serve a strict-square placement elsewhere.
- 1920×1080 (16:9 landscape) — renders as a short strip in a vertical feed. Fine for repurposed slide decks where re-designing isn't worth it; a handicap for anything made fresh.
The trade-off math is the same one that applies to the Instagram carousel size question — portrait wins because pixels on screen are the bid in the attention auction. The difference is only the container: Instagram takes individual images, LinkedIn takes one PDF.
Carousel ads are a different format
One honest caveat before you copy these numbers into an ad campaign: LinkedIn carousel ads are not document posts. The paid format uses individual image cards (1:1) with per-card headlines and links, managed through Campaign Manager — different specs, different limits, different upload flow. Everything on this page covers organic document-post carousels. If you're building ads, pull the current specs from LinkedIn's Campaign Manager docs rather than any organic-size guide, including this one.
Export checklist: from slides to a correct PDF
The path from designed slides to an upload-ready PDF, condensed:
- Design at 1080×1350 from the first slide. Designing small and upscaling later bakes in softness that no export setting can undo.
- Keep source images lossless. Build slides from PNG, not JPG — LinkedIn applies its own compression on upload, and compressing an already-compressed JPG is where artefacts come from.
- Export all slides as one PDF. Figma, Canva, Keynote and Google Slides can all export multi-page PDFs directly. If your tool can't, export PNGs and stitch them with Preview (Mac) or any PDF merger.
- Proof at 100% zoom. Open the PDF and read the smallest text at full size — this is the step that catches soft exports before LinkedIn does.
- Check the file size. Under 100 MB is the hard limit; a typical 10-slide carousel from PNG sources lands well under 20 MB. If you're near the limit, your source images are heavier than they need to be.
- Proofread, then upload. No post-publish edits, so the last read-through is the only one that counts.
Get the size right automatically
Everything above is checkable by hand, and now you know what to check. But it's also the kind of work a tool should simply absorb.
xcarousel treats the spec sheet as a solved problem: pick LinkedIn, and the canvas is 1080×1350 from the first slide; the export is a pixel-exact PDF of what you saw in the editor — correct page size, single file, no rasterisation surprises, ready for the document upload. The same carousel switches to Instagram's format with the design adapting automatically instead of getting cropped. Generate one from your next post idea and check the output against every number on this page.