LinkedIn Document Carousels: PDF Specs That Convert 2026

LinkedIn document posts (the swipeable PDF format) are still the cheapest organic reach on the platform in 2026. The native video push did not kill them. In our own test window (Jan 1 to Mar 31, 2026) carousels beat single-image posts by 3.4x on dwell time and 2.1x on saves. But a surprising number of them render poorly because the PDF itself is wrong. Fonts get substituted, pages get cropped, and the first slide looks soft on mobile.

Here is the spec set we use, tuned for the current LinkedIn viewer.

Page size and aspect ratio

LinkedIn renders document posts inside a fixed viewport. You can upload any PDF, but only two page sizes look sharp without letterboxing:

Aspect	Dimensions (px at 72 DPI)	Use case
1:1 square	1080 x 1080	Default, safest
4:5 portrait	1080 x 1350	Best mobile dwell
1.91:1 landscape	1200 x 628	Rare, looks small on phones

The 4:5 portrait page wins on mobile because it fills more of the thumb-zone before the user decides to swipe away. Square still works if you are also cross-posting to X. Avoid A4 (595 x 842 points) — it gets downsampled and your 10pt body text turns into mush.

Page count

Hard ceiling is 300 pages. Practical ceiling is 12. Engagement drops off a cliff after slide 10 for the median post. The sweet spot from our data:

• Hook slide (1)
• Context (1)
• Meat (6 to 8)
• Recap (1)
• CTA (1)

Fonts

Embed everything. LinkedIn's viewer does not fall back gracefully — if a glyph is missing it substitutes with a serif that breaks your layout. In Figma, export with "Outline text" if you are using anything exotic. In Keynote or Google Slides, export as PDF/A-1b, which forces font embedding.

Minimum sizes that stay legible on a 390px-wide iPhone:

• Body: 28 pt
• Caption: 20 pt
• Headline: 56 pt+

Do not go below 20 pt for anything you want read.

Export settings

The common failure mode is exporting at "print" quality and shipping a 40 MB PDF that LinkedIn silently compresses into jelly. Target under 10 MB even though the hard limit is 100 MB.

Recommended pipeline:

Source (Figma/Keynote) 
  -> PDF export, 150 DPI, sRGB color
  -> Compress images to 85% JPEG or lossless WebP
  -> Flatten transparency
  -> Embed fonts (PDF/A-1b)

If you are assembling the PDF from individual PNG or WebP slides, run them through Konvrt's converter — it handles the image-to-PDF merge in-browser without uploading files to a server, which matters if the deck has unreleased client work on it.

Color and contrast

LinkedIn's dark mode usage crossed 48% of mobile sessions in Q1 2026 per their own engineering blog. Pure white backgrounds now flash uncomfortably. Use #F5F5F5 or a soft off-white, and keep body text at a contrast ratio of 7:1 or better against your background. Check in both light and dark preview before shipping.

The first slide decides everything

You get roughly 1.2 seconds before someone scrolls past. The cover slide needs:

• One concrete number or claim above the fold
• Sans-serif headline, 64 pt minimum
• A visual anchor on the right third (chart, photo, icon)
• No logo in the top-left — it wastes the spot the eye lands on first

Skip the "swipe to learn more" arrow. Everyone already knows.

Common gotchas

• Hyperlinks are clickable on desktop, not mobile. Do not rely on them as your only CTA. Put the URL in the post body.
• Video embedded in the PDF plays as a still frame. Do not bother.
• Exported from Canva? Canva's default PDF uses CMYK for "print" exports. Use "Standard" or "For web" to stay in RGB.
• Emoji rendering is inconsistent. Use SVG icon assets instead if the glyph matters.

Batching the production

If you are producing a weekly carousel, the slowest step is usually converting 10 to 12 individual slide exports into a single PDF. Doing it one file at a time in Acrobat is painful. The batch converter will queue the whole folder and merge in order by filename, which is why most of us name slides 01-hook.png, 02-context.png, and so on.

The takeaway: 4:5 portrait, 28 pt body minimum, fonts embedded, under 10 MB, and fewer than 12 slides. Everything else is decoration.