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

When running B2B campaigns, a poorly cropped image or a truncated headline can instantly kill your conversion rates. LinkedIn is a premier ecosystem for reaching decision-makers, but its technical parameters are famously strict. If your assets do not match the precise platform requirements, your ads will either be rejected during review or fail to capture attention in a crowded professional feed.

Whether you are launching single image campaigns, high-converting carousels, or targeted video ads, getting the specifications right the first time is essential. Here is your definitive, up-to-date guide to LinkedIn paid ad specifications, technical parameters, and formatting constraints.

1. Single Image Ads

Single image ads appear directly in the user’s feed and are among the most versatile tools for driving website traffic, lead generation, and brand awareness.

• Aspect Ratios & Recommended Sizes:
  • Landscape (1.91:1): 1200 × 628 pixels (Desktop and Mobile)
  • Square (1:1): 1200 × 1200 pixels (Desktop and Mobile)
  • Vertical (4:5): 720 × 900 pixels or up to 1080 × 1350 pixels (Mobile only)
• File Types: JPG, PNG, or non-animated GIF
• Maximum File Size: 5 MB
• Ad Copy Best Practices:
  • Introductory Text: Up to 3,000 characters allowed, but 150 characters or fewer is strongly recommended to prevent text truncation above the “see more” break.
  • Headline: Up to 200 characters allowed, but keep it under 70 characters for optimal visibility across all devices.

2. Video Ads

Video is unmatched for demonstrating complex software, showcasing company culture, or telling a compelling B2B brand story.

• Aspect Ratios & Resolution:
  • Landscape (16:9): 1920 × 1080 pixels
  • Square (1:1): 1080 × 1080 pixels
  • Vertical (4:5): 1080 × 1350 pixels (Recommended for mobile feeds)
  • Vertical (9:16): 1080 × 1920 pixels
• File Format: MP4
• File Size Range: 75 KB to 500 MB
• Duration: 3 seconds to 30 minutes (Note: High-performing performance ads generally focus on the first 15–30 seconds).
• Frame Rate & Bitrate: 30 FPS or lower; match your bitrate to standard web publishing standards.
• Thumbnails: PNG or JPG, max 2 MB (must match the video’s aspect ratio).

3. Carousel Ads

Carousel ads let you feature a sequence of 2 to 10 swipeable cards, making them ideal for step-by-step guides, product features, multi-stat stories, or distinct value propositions.

• Card Image Size: 1080 × 1080 pixels (1:1 aspect ratio)
• Number of Cards: 2 to 10 cards per ad
• File Types: JPG or PNG
• Max File Size: Up to 10 MB total for the entire set (or per card depending on configuration; keep individual assets optimized).
• Copy Limits:
  • Introductory Text: Up to 255 characters recommended.
  • Card Headline: Up to 45 characters (ensure text is concise so it doesn’t get cut off).

4. Document Ads

Document ads allow you to share gated or ungated whitepapers, research reports, case studies, or slide decks directly within the LinkedIn feed, keeping users engaged without forcing them to navigate away immediately.

• File Formats: PDF, DOC, DOCX, PPT, or PPTX
• Maximum File Size: Up to 100 MB
• Page Limit: Up to 300 pages (though 5 to 15 pages typically yields the highest engagement rates for native reading).
• Text Specs: Standard introductory text rules apply (aim for under 150 characters for clean presentation).

5. Message and Conversation Ads

Directly reaching prospects via LinkedIn Messaging (Sponsored Messaging) achieves significantly higher open rates than traditional email, provided the copy is conversational and relevant.

• Message Ads / Conversation Ads Specs:
  • Sender Image: Automatically pulls from the designated sender’s personal LinkedIn profile.
  • Message Text: Up to 1,500 characters for Message Ads; up to 8,000 characters for Conversation Ads.
  • Custom Footer / Terms: Up to 2,500 to 20,000 characters depending on specific legal/disclaimer needs.
  • Call-to-Action (CTA) Button: Up to 20–25 characters.
  • Optional Desktop Banner: 300 × 250 pixels (JPG or PNG, max 2 MB). Note: Banners only display on desktop views.

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

Text ads are cost-effective, right-rail text units, while Dynamic Ads personalize themselves using the target user’s profile data (such as their profile photo and name).

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

Key Takeaways for Campaign Success

1. Prioritize Mobile-First Dimensions: A vast majority of LinkedIn traffic happens on mobile devices. Designing with 1:1 square or 4:5 vertical ratios guarantees your ads occupy maximum screen real estate in the feed.
2. Mind the Safe Zones: Keep vital text, logos, and product visuals away from the extreme edges of your creative assets to avoid overlap with native LinkedIn UI elements (like time stamps, play buttons, and profile markers).
3. Keep Copy Concise: While LinkedIn allows long character limits, truncating your message breaks user momentum. Lead with a punchy hook within the first 150 characters of introductory text.