The Ultimate Guide to LinkedIn Ad Sizes and Specs

In the world of B2B marketing, LinkedIn is the premier destination for reaching decision-makers, industry leaders, and high-value prospects. However, even the most compelling copy and brilliant targeting strategy will fall flat if your creative assets are poorly formatted, pixelated, or awkwardly cropped by the platform’s feed layout.

Getting your dimensions right is the non-negotiable first step to protecting your brand image and maximizing your return on ad spend (ROAS). This comprehensive guide breaks down the exact dimensions, aspect ratios, and file requirements for every major LinkedIn ad format.

1. Single Image Ads (Sponsored Content)

Single image ads are the backbone of most LinkedIn campaigns. They appear directly in the user’s feed and can be optimized for three distinct aspect ratios depending on whether you want a traditional look or maximum mobile screen real estate.

• Square (1:1) — Recommended
  • Dimensions: 1200 x 1200 pixels
  • Best For: A versatile, balanced display across both desktop and mobile feeds.
• Vertical (4:5) — Best for Mobile Engagement
  • Dimensions: 1200 x 1500 pixels (or 720 x 900 pixels minimum)
  • Best For: Mobile-first campaigns where you want to dominate vertical screen real estate and capture attention during rapid scrolling. (Note: Delivered on mobile devices only).
• Horizontal / Landscape (1.91:1)
  • Dimensions: 1200 x 627 pixels
  • Best For: Traditional desktop presentations and wide imagery.

Technical Limits:

• File Types: JPG, PNG, or non-animated GIF.
• Maximum File Size: 5 MB.
• Text Limits: Intro text (150 characters recommended), Headline (70 characters).

2. Carousel Ads

Carousel ads allow you to showcase multiple images in a swipeable sequence, making them ideal for telling a step-by-step brand story, breaking down a complex product feature, or highlighting multiple items in a catalog.

• Card Dimensions: Exactly 1080 x 1080 pixels (1:1 square ratio). Note: LinkedIn does not currently support horizontal or vertical carousel cards.
• Card Count: 2 to 10 cards per ad.
• File Types: JPG or PNG.
• Maximum File Size: Up to 10 MB per card.
• Text Limits: Intro text (255 characters), Card headline (45 characters).

Pro Tip: When designing carousels, keep in mind that mobile users only see a portion of the subsequent card. Design the transition from Card 1 to Card 2 to create an innate sense of curiosity that prompts users to swipe.

3. Video Ads

Video is one of the most effective ways to build brand affinity, demonstrate software solutions, or share customer success stories on LinkedIn. LinkedIn supports four primary video orientations:

• Square (1:1): 1080 x 1080 pixels
• Vertical (4:5): 1080 x 1350 pixels (Recommended for mobile)
• Vertical (9:16): Up to 1080 x 1920 pixels
• Landscape (16:9): 1920 x 1080 pixels

Technical Limits:

• File Format: MP4 or MOV.
• File Size: 75 KB up to 5 GB (though keeping files optimized under 500 MB ensures smoother upload and rendering).
• Duration: 3 seconds up to 30 minutes (15 to 30 seconds is typically the sweet spot for performance).

4. Document Ads (Thought Leadership & Content Sharing)

Document ads enable you to gate or share high-value assets—such as whitepapers, research reports, pitch decks, and case studies—directly inside the LinkedIn feed without forcing users to leave the app.

• Supported File Formats: PDF, DOC, DOCX, PPT, or PPTX.
• Maximum Page Count: Up to 300 pages (though 5–15 pages is ideal for maintaining engagement).
• Maximum File Size: 100 MB.
• Orientation: Both portrait and landscape are supported, though landscape or square formatting often provides a cleaner preview experience in the feed.

5. Text Ads & Spotlight Ads (Right-Rail Placements)

If your campaign focuses on cost-effective brand awareness, lead generation, or driving traffic to a newsletter or event, LinkedIn’s desktop right-rail ads offer clean, minimalist options.

• Text Ads:
  • Logo Image: 100 x 100 pixels (JPG or PNG, max 2 MB).
  • Copy Limits: Headline up to 25 characters; description up to 75 characters.
• Spotlight Ads:
  • Company Logo: 100 x 100 pixels.
  • Optional Background Image: 300 x 250 pixels.
  • Copy Limits: Headline up to 50 characters, company name up to 25 characters.

Pro Tips for Flawless LinkedIn Ad Execution

1. Design for Mobile First: Over 60% of LinkedIn traffic originates from mobile devices. Relying exclusively on horizontal (1.91:1) banners means losing valuable screen space. Make square (1:1) or vertical (4:5) your default choices.
2. Mind the Safe Zones: Avoid placing critical text, logos, or call-to-action buttons near the very edges or bottom corners of your images and videos, where timestamps, UI overlays, or card headlines might crop them.
3. Keep Text Legible: When using Document Ads or image overlays, ensure your font size is large enough (minimum 18pt equivalent) to be read comfortably on a smartphone screen without zooming.
4. Test and Iterate: Always preview your ads using LinkedIn Campaign Manager’s preview tool across multiple device types before hitting launch. A quick layout check can save you from truncated headlines and awkward formatting errors.