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

Running high-impact B2B campaigns requires more than just a compelling value proposition and precise audience targeting—it demands technical execution. When an ad creative is rejected for a pixel misalignment or truncated because it ignored character limits, budget and momentum stall.

Whether you are launching single-image brand awareness campaigns, video thought leadership, or multi-card carousels, getting the technical specifications right is the foundational step of modern B2B media buying.

1. Single Image Ads

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

• Aspect Ratios & Recommended Sizes:
  • Square (1:1): 1200 × 1200 pixels (Recommended for multi-device versatility).
  • Landscape (1.91:1): 1200 × 628 pixels.
  • Vertical (4:5): 720 × 900 pixels (Mobile-only feed dominance).
• File Types: JPG, PNG, or non-animated GIF.
• Maximum File Size: 5 MB.
• Copy Limits:
  • Introductory text: 150 characters recommended to prevent truncation on mobile (up to 600 max on desktop).
  • Headline: 70 characters recommended to avoid cutoff (up to 200 max).

2. Video Ads

Video is critical for complex B2B storytelling, product demos, and executive thought leadership. LinkedIn supports multiple aspect ratios depending on how your audience consumes content.

• Aspect Ratios & Resolutions:
  • Landscape (16:9): Min 640 × 360 to Max 1920 × 1080 px.
  • Square (1:1): Min 360 × 360 to Max 1920 × 1920 px.
  • Vertical (4:5): Min 360 × 450 to Max 1536 × 1920 px (Highly recommended for mobile feed real estate).
  • Vertical (9:16): Up to 1080 × 1920 px.
• File Format & Limits: MP4 format, 30 FPS maximum, bitrates matching standard HD outputs. File size ranges from 75 KB to 500 MB.
• Duration: 3 seconds to 30 minutes (though optimal performance for B2B engagement typically sits under 30 seconds).
• Thumbnails & Captions: Custom video thumbnails (JPG/PNG, max 2 MB) matching the video aspect ratio are strongly advised. SRT caption files can be uploaded for sound-off viewing.

3. Carousel Ads

Carousels allow you to showcase multiple products, unpack a step-by-step framework, or tell an evolving brand story across a sequence of swipeable cards.

• Card Count: 2 to 10 cards per ad.
• Image Specifications: 1080 × 1080 pixels (1:1 aspect ratio).
• File Types & Size: JPG, PNG, or non-animated GIF; maximum 10 MB per card.
• Copy Limits:
  • Introductory text: 150 characters recommended (up to 255 max).
  • Card Headline: 45 characters max to prevent awkward line breaks.

4. Document Ads

If your strategy relies on gating deep-dive industry reports, whitepapers, or strategic blueprints, Document Ads let users flip through PDFs natively within the LinkedIn feed without navigating away.

• File Formats: PDF, DOC, DOCX, PPT, or PPTX.
• File Size & Length: Up to 100 MB and a maximum of 300 pages.
• Best Practice: Ensure text elements are high-resolution vector text rather than compressed raster images to guarantee readability on high-density mobile screens.

5. Message and Conversation Ads

Direct-response messaging campaigns deliver targeted propositions straight into a user’s LinkedIn InMail inbox.

• Message Text: Up to 500–1,500 characters depending on the exact format tier, with hyperlinked text capped around 70 characters.
• Call-to-Action (CTA) Button: Up to 25 characters.
• Optional Desktop Banner: 300 × 250 pixels, JPG or PNG, max 2 MB (renders on desktop views only).
• Sender Image: Automatically pulls from the designated sender’s personal LinkedIn profile.

6. Text and Spotlight Ads (Dynamic Ads)

Dynamic ads personalize themselves using the viewer’s profile data (such as their company name, job title, or profile photo) to drive page follows or website traffic.

• Text Ads (Right-Rail):
  • Company logo: 100 × 100 pixels (JPG/PNG, max 2 MB).
  • Headline: 25 characters max.
  • Description: 75 characters max.
• Spotlight Ads:
  • Company logo: 100 × 100 pixels.
  • Optional background image: exactly 300 × 250 pixels (max 2 MB).
  • Headline: up to 50 characters.

Pro-Tips for Creative Success

1. Design for Mobile First: Over 60% of LinkedIn traffic occurs on mobile devices. Prioritize vertical (4:5) frames for single-image and video assets to occupy maximum screen estate.
2. Keep Critical Text Centralized: Avoid placing critical value propositions or logos near the outer margins where UI overlays (like video duration stamps or profile tags) might obscure them.
3. Test Before Launch: Always preview your ads using LinkedIn Campaign Manager’s preview tool to ensure your intro text and headlines truncate gracefully across both desktop and mobile viewports.