The Ultimate Guide to LinkedIn Paid Ad Specs: Formats, Sizes, and Creative Best Practices

When running B2B campaigns, hitting the right target audience is only half the battle. If your creative asset doesn’t match LinkedIn’s technical specifications, your ads risk being awkwardly cropped, rejected during review, or completely ignored by the professionals scrolling through their feeds.

Whether you are launching a brand awareness blitz, generating high-intent leads, or promoting an upcoming industry webinar, adhering to the correct LinkedIn paid ad specs is crucial for campaign success. This complete guide breaks down the dimensions, file sizes, and character limits across LinkedIn’s most popular ad formats.

1. Single Image Ads

Single image ads are the backbone of LinkedIn advertising. They appear directly in the user’s desktop and mobile feed, making them versatile for everything from thought-leadership content to direct-response offers.

• Aspect Ratios & Dimensions:
  • Square (1:1): 1200 x 1200 pixels (Recommended for flexible multi-device delivery)
  • Landscape (1.91:1): 1200 x 628 pixels
  • Vertical (4:5): 720 x 900 pixels (Optimized for mobile-only high-impact delivery)
• File Types: JPG, PNG, or non-animated GIF
• Max File Size: 5 MB
• Copy Limits:
  • Introductory Text: 150 characters recommended (up to 600 max before truncation)
  • Headline: 70 characters recommended (up to 200 max)
  • Description (LinkedIn Audience Network only): 70 characters

2. Video Ads

Video is one of the most effective ways to capture attention in a fast-moving professional feed. LinkedIn supports a variety of orientations depending on your storytelling style.

• Aspect Ratios & Dimensions:
  • Landscape (16:9): 1920 x 1080 pixels
  • Square (1:1): Up to 1920 x 1920 pixels
  • Vertical (4:5): 720 x 900 pixels (Strongly recommended for feed performance)
  • Vertical (9:16): 720 x 1280 to 1080 x 1920 pixels
• File Type: MP4
• File Size: 75 KB (min) to 500 MB (max)
• Duration: 3 seconds to 30 minutes (though 15–30 seconds typically yields the highest completion rates)
• Frame Rate: 30 FPS or lower
• Thumbnails: Optional custom JPG or PNG matching the video’s aspect ratio (Max 2 MB)

3. Carousel Ads

Carousel ads let you showcase multiple scrollable cards within a single ad unit. They are ideal for product feature breakdowns, sequential storytelling, or highlighting multiple content pieces.

• Cards: 2 to 10 cards per ad
• Card Dimensions: 1080 x 1080 pixels (1:1 square)
• File Types: JPG, PNG, or non-animated GIF
• Max File Size: 10 MB per card
• Copy Limits:
  • Introductory Text: Up to 255 characters (applies across all cards)
  • Card Headline: Up to 45 characters per card

4. Document Ads (Thought Leader / Content Downloads)

Document ads allow users to read whitepapers, case studies, or slide decks directly inside the LinkedIn feed without having to navigate to an external landing page.

• File Formats: PDF, DOC, DOCX, PPT, or PPTX
• Max File Size: 100 MB
• Page Limit: Up to 300 pages (shorter, highly visual decks usually perform better)
• Copy Limits: Introductory text follows standard Single Image ad constraints (150–600 characters).

5. Message Ads & Conversation Ads

Sponsored Messaging allows you to deliver targeted, personalized messages straight to a user’s LinkedIn Messaging inbox.

• Sender Info: Uses the profile of a designated sender within your organization.
• Message Text: Up to 1,500 characters
• Call to Action (CTA) Button: Up to 20 characters (with a destination URL up to 1,024 characters)
• Optional Desktop Banner: 300 x 250 pixels (JPG or PNG, max 2 MB) which displays on the right rail of the desktop interface while users view the message.

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

Found primarily on the desktop right-rail, these simple, text-heavy formats are cost-effective for driving steady brand awareness or page followers.

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

Best Practices for LinkedIn Creative Success

1. Design for Mobile First: Over 60% of LinkedIn traffic originates from mobile devices. Vertical (4:5) static images and square or vertical videos take up significantly more screen estate in the mobile feed, leading to higher engagement rates.
2. Hook Them Early: For video ads, place your core brand message or value proposition within the first 3 seconds, as many professionals skim feeds with sound off by default. Incorporating burned-in captions is practically mandatory.
3. Keep Lead Gen Forms Concise: If you are pairing your ads with LinkedIn Lead Gen Forms, stick to 3 to 4 essential fields (