Demystifying LinkedIn Ad Sizes: The Ultimate Guide to Visual Specs for Maximum ROI

When it comes to B2B marketing, LinkedIn is the undisputed heavyweight champion. With over a billion professionals networking, sharing industry insights, and searching for solutions, it’s a goldmine for brands looking to generate high-quality leads.

However, running a successful LinkedIn campaign takes more than just a clever hook and a solid target audience. It requires visual polish. Nothing screams “amateur hour” faster than a stretched corporate headshot, a pixelated carousel card, or text cut off awkwardly at the edges.

To help your brand make a polished, professional impression, here is the complete, definitive guide to LinkedIn ad sizes and specs.

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Why LinkedIn Ad Dimensions Matter

LinkedIn’s feed is a crowded, fast-moving space. Professionals are scrolling through breaking industry news, thought-leadership posts, and messages from colleagues.

Adhering to LinkedIn’s exact specifications ensures that:

1. Your creative isn’t cropped: Platforms automatically crop or stretch images that don’t fit aspect ratios, which can decapitate people or chop off important text.
2. Your message is legible: High-resolution uploads prevent blurriness, keeping your value proposition crisp on both desktop monitors and tiny smartphone screens.
3. You maximize budget efficiency: Clean, professional ads naturally drive higher click-through rates (CTR) and lower your cost-per-click (CPC).

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1. Single Image Ads

The classic, tried-and-true staple of the LinkedIn feed.

Single image ads blend natively into the user’s feed, making them fantastic for driving website traffic, promoting gated content, or announcing brand milestones.

• Landscape (Most Common):
  • Recommended Size: 1200 x 627 pixels
  • Aspect Ratio: 1.91:1
• Square:
  • Recommended Size: 1080 x 1080 pixels
  • Aspect Ratio: 1:1
• Vertical:
  • Recommended Size: 1080 x 1350 pixels (or 600 x 900 pixels)
  • Aspect Ratio: 4:5
• File Formats: JPG or PNG
• Max File Size: 5 MB

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2. Carousel Image Ads

Interactive storytelling at its finest.

Carousel ads allow you to feature a swipeable series of up to 10 cards. They are perfect for showcasing step-by-step guides, breaking down multi-feature product rollouts, or telling a brand story.

• Card Size:
  • Recommended Size: 1080 x 1080 pixels
  • Aspect Ratio: 1:1
• File Formats: JPG or PNG
• Max File Size per Card: 10 MB
• Card Limits: Minimum 2 cards, maximum 10 cards.

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3. Video Ads

Capture attention with motion.

Video is one of the most engaging mediums on LinkedIn. Whether you are running a customer testimonial or a product teaser, getting the aspect ratio right is critical since users consume video across various orientations.

• Landscape:
  • Recommended Size: 1280 x 720 pixels (Aspect Ratio: 16:9)
• Square:
  • Recommended Size: 1080 x 1080 pixels (Aspect Ratio: 1:1)
• Vertical:
  • Recommended Size: 1080 x 1350 pixels or 1080 x 1920 pixels (Aspect Ratio: 9:16 or 4:5)
• File Format: MP4
• File Size Range: 75 KB to 200 MB
• Video Length: 3 seconds to 30 minutes (though keeping shorter versions for feed ads—around 15 to 30 seconds—typically yields the best completion rates).

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4. Thought Leader Ads

Leverage employee advocacy and authentic voices.

Thought Leader Ads let you sponsor organic posts created by your company’s executives, employees, or industry influencers. Because these look and feel like genuine peer recommendations rather than polished corporate banners, they often enjoy higher trust and engagement.

• Image/Video Specs: Follows the same underlying specs as the original organic post format (Single Image, Carousel, or Video).
• Tip: Always ensure the original creator’s profile picture and handle look sharp, as they will be front and center in the ad unit.

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5. Text Ads & Spotlight Ads

Desktop-exclusive sidebar real estate.

If your campaign goals involve quick brand awareness or driving traffic via desktop users, sidebar ads shouldn’t be overlooked.

• Text Ads (Desktop Sidebar):
  • Image Size: 100 x 100 pixels (Optional, but highly recommended)
  • Headline: Up to 25 characters
  • Description: Up to 75 characters
• Spotlight Ads (Personalized Desktop Ads):
  • Company Logo / Image Size: 100 x 100 pixels
  • Background Image (Dynamic variant): 300 x 250 pixels
  • Headline & Description character limits apply.

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6. Document Ads

Deliver high-value gated content directly in the feed.

Document ads let users flip through whitepapers, research reports, or slide decks directly inside the LinkedIn app without needing to click away to a landing page.

• Supported File Types: PDF, DOC, DOCX, PPT, PPTX
• Max Page Count: Up to 300 pages (though 5–15 pages is usually the sweet spot for engagement).
• Orientation: Vertical, horizontal, or square formats are supported, but vertical/square pages render best on mobile screens.

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Best Practices for LinkedIn Ad Design

Knowing the dimensions is only half the battle. To truly stand out in a sea of blue and white UI, keep these design principles in mind:

1. Design for Mobile First: Over 60% of LinkedIn traffic originates from mobile devices. If your text is too small to read on an iPhone or Android device, you’ll lose your audience instantly.
2. Include Clear Branding Early: Don’t wait until the end of a video or a hidden corner of an image to show your logo. Build brand recognition within the first two seconds.
3. Keep Text Concise: While LinkedIn allows text overlays, avoid turning your graphic into a text book. Use bold, punchy headlines and let your ad copy handle the rest.
4. Always Test Variations: A/B test square vs. vertical formats or lifestyle imagery vs. clean graphics to see what resonates most with your unique B2B audience.

By matching your creative assets to LinkedIn’s precise sizing guidelines, you’ll protect your brand’s professional reputation, maximize your creative impact, and turn passive scrollers into high-value pipeline.