The Ultimate Guide to LinkedIn Ad Sizes and Specs: Making Every Pixel Count

In the world of B2B marketing, LinkedIn is the undisputed heavyweight champion. With over a billion professionals networking, sharing industry insights, and making career moves, it offers a goldmine of targeted opportunities for advertisers. But running a successful campaign isn’t just about targeting the right audience—it’s also about visual presentation.

If your ad images look stretched, blurry, or get awkwardly cropped, potential clients will scroll right past them. Understanding and utilizing the correct LinkedIn ad sizes is the secret weapon to driving higher engagement, CTR (click-through rates), and ultimately, ROI.

This comprehensive guide breaks down everything you need to know about LinkedIn ad formats and their precise dimensions so you can design campaigns that look sharp, professional, and built to convert.

Why LinkedIn Ad Sizes Matter

First impressions matter. On a platform driven by professionals, your ad design reflects your brand’s credibility. Using the correct aspect ratios and dimensions ensures that:

• Your creative isn’t compromised: Platforms often automatically crop images that don’t fit specifications, potentially cutting off key headlines or logos.
• Your text remains legible: Crisp, properly scaled typography prevents eye strain and ensures your call-to-action (CTA) is crystal clear.
• Your ads are optimized for mobile: A significant portion of LinkedIn’s traffic browses via smartphones and tablets. Responsive, correctly sized assets guarantee a seamless mobile experience.

1. Single Image Ads

Single image ads appear directly in the LinkedIn feed, mixing seamlessly with organic content. They are versatile, easy to set up, and ideal for driving website traffic or lead generation.

• 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
  • Aspect Ratio: 4:5
• File Formats: JPG or PNG
• Max File Size: 5 MB

Pro Tip: Vertical ads take up more vertical real estate on mobile feeds, often resulting in higher visibility and engagement rates compared to traditional landscape formats.

2. Carousel Image Ads

Carousel ads let you showcase a series of up to 10 swipeable cards. They are fantastic for telling a step-by-step story, highlighting multiple product features, or breaking down a detailed case study.

• Recommended Size: 1080 x 1080 pixels per card
• Aspect Ratio: 1:1
• File Formats: JPG or PNG
• Max File Size: 10 MB per card
• Card Limit: 2 to 10 cards per carousel

3. Video Ads

Video is one of the most engaging mediums on LinkedIn. Whether you’re launching a product teaser, sharing customer testimonials, or delivering a thought-leadership snippet, video grabs attention fast.

• Landscape Video:
  • Recommended Size: 1280 x 720 pixels (16:9)
• Square Video:
  • Recommended Size: 1080 x 1080 pixels (1:1)
• Vertical Video:
  • Recommended Size: 1080 x 1350 pixels (4:5) or 1080 x 1920 pixels (9:16)
• File Formats: MP4
• File Size Range: 75 KB to 200 MB
• Duration: 3 seconds to 30 minutes (though 15–30 seconds typically performs best for retention)

4. Document Ads (Lead Gen Content)

Document ads let users read PDFs, slide decks, or whitepapers directly within the LinkedIn feed without having to leave the app. This format is a powerhouse for top-of-funnel lead generation.

• File Types Accepted: PDF, DOC, DOCX, PPT, PPTX
• Max File Size: 100 MB
• Orientation: Portrait or Landscape (Portrait/Vertical generally fits mobile screens better)

5. Message Ads (Sponsored Messaging)

Message ads allow you to send direct, personalized messages to your target audience’s LinkedIn InMail inbox. They work like email marketing inside LinkedIn, offering high open rates.

• Custom Banner Image (Optional Desktop Side Rail):
  • Recommended Size: 300 x 250 pixels
  • File Formats: JPG, GIF (non-animated), or PNG
  • Max File Size: 2 MB
• Text Limits: Subject line (up to 60 characters), Message body (up to 1,500 characters recommended).

6. Follower Ads (Dynamic Ads)

Dynamic ads personalize themselves using the target user’s profile data (like their profile picture, first name, and job title) to drive followers to your LinkedIn Company Page.

• Company Logo (Square):
  • Recommended Size: 100 x 100 pixels (minimum)
• Custom Background Image (Optional):
  • Recommended Size: 300 x 250 pixels
• Text Limits: Ad description (up to 70 characters), Headline (up to 50 characters).

Best Practices for LinkedIn Ad Design

1. Prioritize Mobile: Over 60% of LinkedIn traffic originates from mobile devices. Always preview your ads on a smartphone screen before pushing them live.
2. Keep Text Minimal on Images: Keep overlay text clean and concise. If you are using images with heavy text, automated tools might flag or restrict your ad delivery.
3. Include a Strong CTA: Whether it’s “Learn More,” “Download Now,” or “Register,” pair your visual asset with an action-oriented button.
4. Test and Iterate: Don’t rely on a single layout. Run A/B tests using different aspect ratios (like square vs. vertical) to see which resonates best with your specific B2B audience.

By aligning your creative assets with LinkedIn’s exact specifications, you ensure your brand looks polished, professional, and primed to capture high-value leads.