The Ultimate Guide to LinkedIn Ad Sizes & Specs

When it comes to B2B marketing, LinkedIn is the premier arena for reaching decision-makers, industry experts, and high-value professionals. However, running a high-performing campaign takes more than just a great targeting strategy—it requires flawless visual execution.

Even the most compelling copy will fall flat if your creative asset gets awkwardly cropped, pixelated, or rejected by LinkedIn’s strict platform parameters.

This comprehensive guide breaks down the essential LinkedIn ad sizes and specifications, categorized by format, so your campaigns look sharp, professional, and built to convert.

1. Single Image Ads (Sponsored Content)

Single image ads are the backbone of most LinkedIn strategies. They appear natively in the user’s feed alongside regular organic posts. Because they support multiple aspect ratios, choosing the right shape determines how much screen real estate you command.

• Square (Recommended):
  • Dimensions: $1200 times 1200$ px (1:1 ratio)
  • Why use it: It works seamlessly across both desktop and mobile feeds, taking up a healthy chunk of vertical space without getting cut off.
• Landscape:
  • Dimensions: $1200 times 628$ px (1.91:1 ratio)
  • Why use it: Great for traditional banner-style creatives, though it takes up less vertical space in the mobile feed.
• Vertical:
  • Dimensions: $720 times 900$ px (4:5 ratio)
  • Why use it: Mobile-only delivery. It commands maximum attention as users scroll on their phones.
• Technical Limits: Maximum file size is 5 MB; accepted formats include JPG, PNG, and non-animated GIF.

2. Video Ads

Video is one of the most effective ways to capture attention, tell a brand story, or demo a complex B2B product. LinkedIn supports horizontal, vertical, and square video formats.

• Landscape (16:9): $1920 times 1080$ px
• Square (1:1): $1920 times 1920$ px (max)
• Vertical (4:5 – Recommended for Mobile): $720 times 900$ px or up to $1080 times 1350$ px
• Vertical (9:16): $720 times 1280$ px up to $1080 times 1920$ px
• Technical Limits:
  • Format: MP4
  • File Size: 75 KB to 500 MB
  • Duration: 3 seconds up to 30 minutes (though short, punchy clips under 30 seconds usually yield the best engagement).

3. Carousel Ads

Carousel ads let you showcase up to 10 swipeable cards. They are ideal for step-by-step guides, multi-product highlights, or telling a sequential brand story.

• Card Dimensions: $1080 times 1080$ px (1:1 ratio mandatory)
• Card Count: 2 to 10 cards
• Technical Limits:
  • File Size: Maximum 10 MB per card
  • Formats: JPG, PNG, or static GIF
  • Text Limits: Headline max 45 characters; description max 255 characters.

4. Document Ads

Want to share a deep-dive whitepaper, annual report, or research deck directly in the feed without forcing users to jump to an external landing page? Document ads allow users to page right through PDFs or slide decks natively.

• Supported File Types: PDF, DOC, DOCX, PPT, PPTX
• Technical Limits:
  • File Size: Up to 100 MB
  • Page Limit: Up to 300 pages (sweet spot is usually under 10 pages for optimal consumption).

5. Message & Conversation Ads

Delivered straight into a prospect’s LinkedIn Messaging (InMail) inbox, these ads offer a high-personalization approach to lead generation.

• Companion Banner (Desktop Only):
  • Dimensions: $300 times 250$ px
  • File Size: Max 2 MB (JPG, PNG, or non-animated GIF)
• Copy Structure: Keep messages concise. While character limits allow up to several thousand characters, shorter, conversational text paired with clear Call-to-Action (CTA) buttons heavily outperforms dense blocks of text.

6. Text & Dynamic Ads (Right-Rail Formats)

Right-rail ads are budget-friendly options that appear exclusively on the desktop version of LinkedIn.

• Text Ads:
  • Logo Size: $100 times 100$ px (JPG or PNG, max 2 MB)
  • Copy Limits: Headline up to 25 characters; description up to 75 characters.
• Spotlight & Follower Ads (Dynamic):
  • Logo/Image Size: $100 times 100$ px
  • Optional Background Image (Spotlight Ads): $300 times 250$ px
  • Copy Limits: Headline up to 50 characters; description up to 70 characters.

💡 Pro-Tip for Marketers: Always preview your ads using LinkedIn’s campaign manager preview tool before pushing campaigns live. Ensuring your text safe zones are respected—especially on mobile vertical and carousel formats—will save your team time, prevent ad rejections, and protect your return on ad spend (ROAS).