The Complete Guide to LinkedIn Ad Sizes and Specs

Running ads on LinkedIn without checking your dimensions first is an expensive guessing game. Because LinkedIn caters to a professional audience scrolling through dense feeds on mobile and desktop devices, mismatched creative specs don’t just look sloppy—they trigger automatic cropping, blurry compression, or outright campaign rejections.

Whether you are launching a high-intent B2B demand-gen campaign or scaling thought leadership, getting your pixels right is step zero. This guide breaks down the exact dimensions, file limits, and best practices for every major LinkedIn ad format.

1. Single Image Ads (Sponsored Content)

Single image ads are the backbone of most LinkedIn campaigns. They appear directly in the user’s feed and support three distinct aspect ratios depending on your placement and strategy.

| Orientation | Recommended Size | Aspect Ratio | Delivery | Max File Size |
| :— | :— | :— | :— | :— |
| Landscape | $1200 times 628$ px | $1.91:1$ | Desktop & Mobile | 5 MB |
| Square | $1200 times 1200$ px | $1:1$ | Desktop & Mobile | 5 MB |
| Vertical | $720 times 900$ px | $4:5$ | Mobile Only | 5 MB |

• File Types: JPG, PNG, or non-animated GIF.
• Pro Tip: Square ($1:1$) is the most versatile choice if you want a single asset that renders reliably across both desktop feeds and mobile screens without unexpected edge clipping.

2. Carousel Image Ads

Carousels let you tell a sequential story, showcase a product suite, or present a step-by-step framework across multiple swipeable cards.

• Card Dimensions: $1080 times 1080$ pixels ($1:1$ square).
• Card Count: 2 to 10 cards per carousel.
• Max File Size: 10 MB per card.
• File Types: JPG or PNG.
• Copy Limits: Card headlines max out at 45 characters, and introductory text allows up to 255 characters.

Rule of Thumb: Keep a consistent visual template across all cards. Mixing aspect ratios or resolutions mid-carousel will force awkward layout shifts for your audience.

3. Video Ads

Video is a powerful tool for building brand authority or walking prospects through software demos, but LinkedIn’s video encoder is strict about frame bounds.

• Supported Aspect Ratios:
  • Landscape (16:9): $1920 times 1080$ px
  • Square (1:1): Up to $1920 times 1920$ px
  • Vertical (4:5): $720 times 900$ px recommended
  • Vertical (9:16): $720 times 1280$ px up to $1080 times 1920$ px
• File Size & Length: Between 75 KB and 500 MB; durations can range from 3 seconds up to 30 minutes (though 15–30 seconds typically wins on engagement).
• Format: MP4.

4. Document Ads (Lead Gen / Content Upgrades)

If you are promoting an industry report, whitepaper, or cheat sheet directly in the feed, Document Ads allow users to flip through pages without leaving LinkedIn.

• Accepted File Formats: PDF, PPT, PPTX, DOC, or DOCX.
• Size Limit: Up to 100 MB (and max 300 pages).
• Design Note: Design your slides in a clean square or portrait orientation. Avoid cramming tiny text into the margins, as mobile users will struggle to read dense paragraphs.

5. Text Ads & Dynamic Ads (Spotlight / Follower)

These smaller units occupy prime real estate on the desktop right-rail.

• Text Ads: Require a simple $100 times 100$ px company logo (JPG/PNG, max 2 MB) paired with a 25-character headline and 75-character description.
• Spotlight Ads: Use a $100 times 100$ px logo alongside an optional $300 times 250$ px background image container.
• Message & Conversation Ads: While the primary asset is text-based messaging, you can attach an optional $300 times 250$ px desktop banner image (max 2 MB) to accompany the chat interface.

Summary Checklist Before You Export

1. Match ratio to placement: Use square ($1:1$) or landscape ($1.91:1$) if you need a universal asset; reserve vertical ($4:5$) strictly for mobile-targeted campaigns.
2. Watch the file weight: Keep single images under 5 MB and carousel cards under 10 MB to prevent upload errors or lagging render times.
3. Protect your safe zones: Keep critical text and logos away from the absolute edges of your frames to survive automated platform cropping.