The Ultimate Guide to LinkedIn Ad Sizes and Specs

Running high-performing campaigns on LinkedIn requires more than just a sharp message and a targeted audience. If your creative assets are improperly sized, LinkedIn’s Campaign Manager will either reject them outright or—worse—display them with awkward cropping, blurry scaling, and lower engagement rates.

Because professionals consume content across multiple devices, mastering the technical blueprint of LinkedIn ad sizes is critical. This comprehensive guide covers exact dimensions, file formats, and best practices for every major LinkedIn ad format.

1. Single Image Ads (Sponsored Content)

Single image ads are the backbone of LinkedIn advertising. They appear directly in the user’s desktop and mobile feed, making versatility a necessity.

• Landscape (1.91:1):
  • Recommended Size: 1200 x 628 pixels
  • Best for: Traditional desktop viewing and safe multi-platform asset repurposing.
• Square (1:1):
  • Recommended Size: 1200 x 1200 pixels
  • Best for: Equal visual weight on both desktop and mobile feeds.
• Vertical (4:5):
  • Recommended Size: 720 x 900 pixels
  • Best for: Mobile-first campaigns. It maximizes vertical screen real estate in the feed.
• File Requirements: JPG, PNG, or GIF (non-animated); maximum file size of 5 MB.

Pro Tip: Keep your core text and focal points centered. Avoid placing critical messaging right against the edges where UI overlays or auto-cropping might clip them.

2. Carousel Ads

Carousels allow you to tell a sequential story, showcase multiple product features, or highlight a step-by-step process using swipeable cards.

• Card Dimensions: 1080 x 1080 pixels (1:1 Square)
• Card Count: 2 to 10 cards per ad (up to 20 slides if utilizing document-style setups).
• File Requirements: JPG, PNG, or static GIF; maximum 10 MB per card.
• Text Limits:
  • Card Headline: Max 45 characters
  • Introductory Text: Max 255 characters

3. Video Ads

LinkedIn users spend significant time watching video content. To capture attention in a professional environment, your video exports must align cleanly with native aspect ratios.

| Aspect Ratio | Recommended Production Size | Notes |
| :— | :— | :— |
| 16:9 Landscape | 1920 x 1080 px | Great for widescreen or repurposed webinar footage. |
| 1:1 Square | 1080 x 1080 px | Balanced performance across desktop and mobile. |
| 4:5 Vertical | 720 x 900 px (or 1080 x 1350 px) | Highly recommended for mobile engagement. |
| 9:16 Vertical | 1080 x 1920 px | Maximum vertical space (use safe zones carefully). |

• File Format: MP4
• File Size: 75 KB to 500 MB
• Duration: 3 seconds up to 30 minutes (though 15–30 seconds typically yields the highest completion rates for top-of-funnel ads).

4. Document Ads

Document ads enable you to directly share whitepapers, case studies, or slide decks right inside the feed, prompting users to flip through pages without leaving LinkedIn.

• File Types: PDF (strongly recommended to preserve vector clarity and fonts), PPT, PPTX, DOC, or DOCX.
• Max File Size: 100 MB (Keep under 3 MB for lightning-fast mobile loading).
• Page Count: Up to 300 pages (8 to 12 slides/pages typically drives optimal engagement).

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

Though smaller in scale, right-rail placements are fantastic for continuous brand reinforcement and direct lead generation.

• Text Ads:
  • Logo Size: 100 x 100 pixels (JPG or PNG, max 2 MB)
  • Copy Limits: Headline up to 25 characters; Description up to 75 characters.
• Spotlight & Follower Ads:
  • Company Logo: 100 x 100 pixels
  • Optional Background Image: 300 x 250 pixels (Spotlight ads only)

Quick Checklist Before You Publish

1. Double-check your file weight: Large PNGs often trigger compression errors or upload rejections. Keep static images well under the maximum file limits.
2. Verify mobile appearance: Preview your ad using LinkedIn Campaign Manager’s mobile preview tool to ensure text isn’t cut off by native profile headers or CTA buttons.
3. Strict adherence to character counts: Write your hooks compactly so they aren’t truncated mid-sentence with an ellipsis.

By matching your creative builds to these exact specs, you ensure your campaigns look polished, professional, and optimized for maximum conversion.