The Complete Guide to LinkedIn Paid Ad Specs: Dimensions, Limits, and Creative Best Practices

Running successful B2B campaigns requires more than just compelling copy and precise audience targeting. If your creative assets don’t match LinkedIn’s technical specifications, your ads will face rejection, formatting awkwardness, or sub-optimal delivery.

Whether you are launching a thought leadership push, driving lead generation forms, or scaling brand awareness, staying on top of LinkedIn’s exact ad dimensions and character limits is critical. This comprehensive guide breaks down the technical specs across all major LinkedIn ad formats to help you design flawless campaigns.

1. Single Image Ads

Single image ads appear directly in the LinkedIn feed and are the backbone of most paid social strategies. They offer flexibility across desktop and mobile.

• Aspect Ratios & Recommended Sizes:
  • Square (1:1): 1200 × 1200 px (Recommended for cross-device delivery)
  • Landscape (1.91:1): 1200 × 628 px
  • Vertical (4:5): 720 × 900 px (Mobile-only; yields high engagement rates)
• File Types: JPG, PNG, or static GIF
• Max File Size: 5 MB
• Copy Limits:
  • Introductory Text: 150 characters recommended before truncation (“see more” button) (up to 600 max)
  • Headline: 70 characters recommended before truncation (up to 200 max)

2. Video Ads

LinkedIn video ads capture attention quickly in the feed and are ideal for product walkthroughs, customer testimonials, and brand storytelling.

• Aspect Ratios & Resolutions:
  • Landscape (16:9): 1920 × 1080 px
  • Square (1:1): Up to 1920 × 1920 px
  • Vertical (4:5): 720 × 900 px (Recommended for mobile feeds)
  • Vertical (9:16): Up to 1080 × 1920 px
• File Type: MP4
• File Size: 75 KB to 500 MB
• Duration: 3 seconds to 30 minutes (15 to 30 seconds typically drives the strongest engagement)
• Frame Rate: 30 FPS or lower

3. Carousel Ads

Carousels let you tell a sequential story or showcase a product lineup across multiple swipeable cards.

• Card Count: 2 to 10 cards per ad
• Image Dimensions: 1080 × 1080 px (1:1 aspect ratio)
• File Types: JPG or PNG (non-animated)
• Max File Size: 10 MB per card
• Copy Limits:
  • Card Headline: 45 characters max (if linked) or 30 characters (if unlinked)
  • Introductory Text: Up to 255 characters

4. Document Ads

Document ads allow users to read and interact with native content—such as whitepapers, e-books, or research reports—directly inside the LinkedIn feed without navigating to an external landing page.

• Supported File Types: PDF, DOC, DOCX, PPT, PPTX
• Max File Size: 100 MB
• Page Limit: Up to 300 pages (though 10 to 20 pages generally yields optimal completion and engagement)

5. Message & Conversation Ads

Delivered directly to a target professional’s LinkedIn Messaging inbox, these formats allow for personalized outreach and interactive, branching pathways.

• Message Ads Specs:
  • Subject Line: 60 characters max
  • Message Body: 1,500 characters max
  • CTA Button: 20 characters max
  • Optional Desktop Banner: 300 × 250 px (JPG/PNG, max 2 MB)
• Conversation Ads Specs:
  • Message Text: Up to 1,500 characters per step
  • Custom CTAs: Up to 5 interactive buttons per prompt
  • Optional Desktop Banner: 300 × 250 px (JPG/PNG, max 2 MB)

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

These right-rail ad units are cost-effective choices for steady, always-on brand awareness and lead generation.

• Text Ads:
  • Logo / Image: 100 × 100 px (JPG or PNG, max 2 MB)
  • Headline: 25 characters max
  • Description: 75 characters max
• Spotlight Ads:
  • Company Logo: 100 × 100 px (JPG or PNG, max 2 MB)
  • Background Image (Optional): 300 × 250 px
  • Headline: 50 characters max
  • Description: 70 characters max
  • CTA Text: 18 characters max

7. Connected TV (CTV) Ads

For enterprise brands looking to reach B2B decision-makers during their downtime, LinkedIn supports Connected TV placements.

• Resolution: 1920 × 1080 px (16:9 aspect ratio)
• File Type: MP4
• Duration: 6 to 60 seconds
• Max File Size: 500 MB

Quick Design Tips for Higher Conversion

1. Design for Mobile First: Over 60% of LinkedIn traffic occurs on mobile devices. Prioritize square (1:1) or vertical (4:5) frames for feed ads to secure more screen real estate.
2. Mind the Safe Zones: Keep crucial text and logos centered to prevent them from being obscured by UI overlays, timestamps, or profile avatars.
3. Keep Copy Concise: While LinkedIn allows longer character limits, truncation happens quickly. Put your strongest value proposition in the first line of your intro text.