Master the Feed: The Definitive Guide to LinkedIn Paid Ad Specs

Running B2B campaigns on LinkedIn offers unparalleled access to decision-makers, industry leaders, and high-value buyers. However, LinkedIn is notoriously unforgiving when it comes to creative parameters. Upload an asset that misses the mark by a few pixels or write a headline that breaks character limits, and you risk cropping, poor rendering, or a flat-out rejection from Campaign Manager.

To maximize your return on ad spend (ROAS) and protect your brand’s professional image, you need a precise blueprint of LinkedIn’s technical parameters. Here is your complete, up-to-date guide to LinkedIn paid ad specifications across all major formats.

1. Single Image Ads

Single image ads are the backbone of most B2B content strategies, appearing natively in the desktop and mobile feeds.

• Aspect Ratios: Landscape (1.91:1), Square (1:1), and Vertical (4:5).
• Recommended Dimensions:
  • Landscape: 1200 × 628 px
  • Square: 1200 × 1200 px
  • Vertical (Mobile Only): 720 × 900 px (or up to 1080 × 1350 px)
• File Types: JPG, PNG, or GIF (non-animated)
• Max File Size: 5 MB
• Copy Specs:
  • Introductory Text: 150 characters recommended (hard cap around 3,000 characters, though text past 150 characters is typically truncated).
  • Headline: 70 characters recommended (hard cap at 200 characters).

Pro Tip: While landscape images are traditional, vertical (4:5) assets capture significantly more real estate on mobile feeds, often driving higher click-through rates (CTR).

2. Video Ads

Video is unmatched for demonstrating complex software solutions, showcasing customer success stories, or building executive thought leadership.

• Aspect Ratios & Resolutions:
  • Landscape (16:9): 1920 × 1080 px
  • Square (1:1): 1080 × 1080 px
  • Vertical (4:5): 1080 × 1350 px (Recommended for mobile)
  • Vertical (9:16): 1080 × 1920 px
• File Format: MP4
• Frame Rate: 30 FPS or lower
• File Size: 75 KB (min) to 500 MB (max)
• Duration: 3 seconds to 30 minutes (though 15–30 seconds typically yields the strongest completion rates for lead generation).
• Thumbnails: JPG or PNG, matching the video’s aspect ratio, max 2 MB.
• Copy Specs: Same as single image ads (150 chars intro text, 70 chars headline).

3. Carousel Ads

Carousels allow you to tell a sequential story, display a multi-product feature set, or break down a step-by-step framework across multiple swipeable cards.

• Number of Cards: 2 to 10 cards
• Card Dimensions: 1080 × 1080 px (1:1 aspect ratio)
• File Types: JPG or PNG (non-animated)
• Max File Size: 10 MB total for the entire ad (or per card limits depending on asset distribution, keeping assets compact is safest).
• Copy Specs:
  • Card Headline: 45 characters max (for ads directing to a landing page).
  • Introductory Text: 255 characters recommended.

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.

• File Formats: PDF, DOC, DOCX, PPT, or PPTX
• Page Limit: Up to 300 pages
• Max File Size: 100 MB
• Copy Specs: Standard 150-character intro text and 70-character headline apply.

5. Thought Leader Ads

A powerful format designed to amplify organic posts written by company executives or employees. Rather than building an ad from scratch, you promote an existing post from a real profile.

• Specs: Follow the underlying native post constraints (text posts, image posts, or video posts). Ensure the creator profile is fully optimized and authorized within Campaign Manager before launch.

6. Message Ads & Conversation Ads

Delivered directly to a user’s LinkedIn Messaging inbox, these formats bypass the traditional feed for a high-intent, 1-to-1 conversational experience.

• Sender Image: Pulls directly from the designated sender’s personal LinkedIn profile.
• Optional Desktop Banner: 300 × 250 px (JPG or PNG, max 2 MB).
• Message Ads Copy:
  • Subject Line: Up to 60 characters.
  • Message Body: Up to 1,500 characters.
  • CTA Button: Up to 20 characters.
• Conversation Ads Copy:
  • Message Text: Up to 8,000 characters (supports branching pathways and multiple response options).
  • CTA Button: Up to 25 characters.

7. Dynamic Ads (Spotlight & Text Ads)

Dynamic ads personalize themselves using the target user’s profile data (such as their profile photo, company name, or job title).

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

Summary Checklist for Campaign Success

1. Design for Mobile First: Over 65% of B2B traffic happens on mobile devices. Prioritize square (1:1) or vertical (4:5) frames over standard landscape boxes.
2. Respect the Safe Zones: Keep crucial text and logos away from the extreme edges of your image or video files to prevent cropping UI overlaps.
3. Keep Copy Concise: While character limits allow for lengthy blocks, keeping headlines under 70 characters and intro text punchy ensures your core message is never truncated behind a “See more” link.