Mastering LinkedIn Paid Ad Specs: The Ultimate Blueprint for B2B Campaign Success

When launching a B2B marketing campaign, your targeting strategy and messaging can be spot-on, but if your creative asset fails to meet technical requirements, your campaign stalls before it even starts. LinkedIn rejects or truncates improperly formatted ads, leading to wasted hours and delayed momentum.

Navigating LinkedIn’s ad specifications requires precision. This comprehensive guide covers the core technical dimensions, file types, and character limits for every major LinkedIn ad format, ensuring your next campaign runs smoothly, looks sharp, and converts effectively.

1. Single Image Ads

Single image ads are the backbone of LinkedIn advertising, appearing directly in the professional feed across desktop and mobile devices.

• Aspect Ratios & Recommended Sizes:
  • Landscape (1.91:1): 1200 × 628 pixels (Delivers to desktop and mobile)
  • Square (1:1): 1200 × 1200 pixels (Recommended for cross-device consistency)
  • Vertical (4:5): 720 × 900 pixels (Optimized for mobile-feed performance)
• File Types & Size: JPG, PNG, or GIF; Maximum file size of 5 MB.
• Copy Limits:
  • Introductory Text: 150 characters recommended (truncates gracefully up to 600).
  • Headline: 70 characters recommended.

2. Video Ads

Video is unmatched for demonstrating product value, sharing customer stories, or establishing thought leadership.

• 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): 1080 × 1920 px
• Technical Specifications:
  • File Format: MP4
  • File Size: 75 KB to 500 MB
  • Duration: 3 seconds to 30 minutes (though 15–30 seconds typically yields the highest engagement).
  • Frame Rate: 30 FPS recommended.
  • Thumbnails: JPG or PNG, max 2 MB (must match the video’s aspect ratio).
• Copy Limits: Introductory text (150 chars recommended) and Headline (70 chars recommended).

3. Carousel Ads

Carousel ads let you showcase a sequence of up to 10 cards, making them ideal for step-by-step guides, feature breakdowns, or distinct product lines.

• Card Dimensions: 1080 × 1080 pixels (1:1 aspect ratio).
• Number of Cards: 2 to 10 cards.
• File Types & Size: JPG, PNG, or non-animated GIF; Maximum 10 MB per card.
• Copy Limits:
  • Card Headline: 45 characters (for ads directing to a landing page).
  • Introductory Text: Up to 255 characters.

4. Document Ads

Document ads allow users to read whitepapers, research reports, or slide decks directly within the LinkedIn feed without navigating to an external landing page.

• Supported File Formats: PDF, PPT, PPTX, DOC, or DOCX.
• File Size & Page Limits: Up to 100 MB and a maximum of 300 pages.
• Copy Limits: Introductory text (150 characters recommended) and Document title (up to 60 characters).

5. Conversation Ads & Message Ads

Sponsored messaging delivers personalized content straight to a target professional’s LinkedIn InMail inbox.

• Message Ads (Single-CTA):
  • Sender: Uses a designated sender’s profile.
  • Message Text: Up to 1,500 characters.
  • Call to Action (CTA): Up to 20 characters.
• Conversation Ads (Branching Paths): Offers multiple pathways based on user choice. Accommodates custom buttons and multi-step messaging flows.
• Optional Desktop Banner: 300 × 250 pixels (JPG/PNG, max 2 MB). Note: Displayed exclusively on desktop feeds.

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

Text and dynamic ads are desktop-only formats that run along the right rail of the LinkedIn interface, acting as cost-effective options for brand awareness and follower acquisition.

• Text Ads:
  • Logo/Image: 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 (max 2 MB).
  • Optional Background Image: 300 × 250 pixels (max 2 MB).
  • Headline: Up to 50 characters.
  • Description: Up to 70 characters.

Best Practices for Seamless Execution

1. Design for Mobile First: Over 60% of LinkedIn traffic occurs on mobile devices. Prioritize vertical (4:5) single-image assets or square (1:1) formats to capture maximum screen real estate.
2. Keep Text Clean: Avoid cramming dense paragraphs into your image creative. Keep critical overlays large and legible on smaller smartphone screens.
3. Double-Check Compression: Always export your assets right at the maximum allowable limits (