LinkedIn Paid Ad Specs & Sizes Guide: Complete Format List

The Ultimate Blueprint to LinkedIn Paid Ad Specs

Running successful campaigns on LinkedIn requires more than just a compelling pitch—it demands technical precision. Because LinkedIn is the premier professional network, your ads need to look sharp, load instantly, and fit seamlessly into feeds across desktop and mobile devices.

If an image is cropped awkwardly or a video file is rejected due to an encoding error, your budget stalls before it even starts. This comprehensive guide outlines the essential technical specifications and creative limits for LinkedIn’s most popular paid ad formats.

1. Single Image Ads

Single image ads appear directly in the user’s feed and are versatile for promoting blog posts, whitepapers, product updates, or brand awareness.

• Landscape (1.91:1): 1200 x 628 pixels (Desktop and mobile)
• Square (1:1): 1200 x 1200 pixels (Recommended for multi-platform consistency)
• Vertical (4:5): 720 x 900 pixels (Mobile feed optimization)
• File Types: JPG, PNG, or GIF (non-animated)
• Maximum File Size: 5 MB
• Introductory Text: Keep under 150 characters to prevent truncation on mobile (hard cap at 600 characters)
• Headline: 70 characters recommended to avoid mobile truncation (hard cap at 200 characters)

2. Video Ads

Video is one of the best ways to capture attention in a professional feed, especially since most users watch on mobile devices where vertical formats dominate.

| Aspect Ratio | Recommended Resolution | Min/Max Dimensions |
| :— | :— | :— |
| Square (1:1) | 1080 x 1080 px | 360 x 360 to 1920 x 1920 px |
| Vertical (4:5) | 1080 x 1350 px | 360 x 450 to 1080 x 1350 px |
| Vertical (9:16) | 1080 x 1920 px | 360 x 640 to 1080 x 1920 px |
| Landscape (16:9) | 1920 x 1080 px | 640 x 360 to 1920 x 1080 px |

• File Format: MP4
• File Size: 75 KB to 500 MB
• Duration: 3 seconds to 30 minutes (15 to 30 seconds is the sweet spot for engagement)
• Frame Rate: 30 FPS or lower
• Thumbnails: Custom thumbnails must match the video’s aspect ratio and be under 2 MB (JPG or PNG).

Pro Tip: LinkedIn videos autoplay on mute by default. Always hardcode or upload closed captions (.srt format) to ensure your message lands even with the sound off.

3. Carousel Ads

Carousels let you showcase a sequence of up to 10 cards, making them ideal for step-by-step guides, product features, or split data points.

• Card Dimensions: 1080 x 1080 pixels (1:1 aspect ratio)
• Number of Cards: 2 to 10 cards
• File Types: JPG or PNG (non-animated)
• Max File Size: 10 MB per card
• Card Headline: 45 characters max (recommended to prevent clipping)
• Introductory Text: 150 characters recommended limit

4. Document Ads

Document ads allow you to share native content—like deep-dive industry reports, e-books, or slide decks—directly inside the LinkedIn feed without forcing users to visit an external landing page.

• Supported File Formats: PDF, DOC, DOCX, PPT, PPTX
• Maximum File Size: 100 MB
• Maximum Page Count: Up to 300 pages (though 5–15 pages typically performs best for engagement).

5. Message and Conversation Ads

Delivered directly to a user’s LinkedIn Messaging inbox, these ads offer a personalized outreach approach.

• Sender: Must be sent from a verified profile connected to your organization.
• Message Text: Up to 1,500 characters (Message Ads) or split branches in Conversation Ads.
• Call-to-Action (CTA) Button: 20 to 25 characters max.
• Optional Companion Banner: 300 x 250 pixels (JPG, PNG, max 2 MB), displayed on the desktop sidebar.

Quick Checklist Before You Launch

1. Double-Check Mobile Ratios: Over 70% of professional traffic happens on mobile. Prioritize square (1:1) or vertical (4:5/9:16) assets for feed campaigns to maximize screen real estate.
2. Mind the Text Safe Zones: Keep your primary value propositions and hooks in the center of your creative assets to avoid getting cut off by profile overlays or UI buttons.
3. Verify Destination Links: Ensure tracking parameters (UTMs) are appended correctly before finalizing your ad setup.