The Complete Guide to LinkedIn Paid Ad Specs: Dimensions, Limits, and Creative Blueprints

Navigating LinkedIn’s advertising ecosystem requires more than a compelling hook and a strong B2B target audience—it demands precision. Unlike platforms where creative can easily flex across placements, LinkedIn has strict technical guidelines. A single pixel error can trigger blurry scaling, and text that exceeds character limits will face awkward truncations in the feed.

This definitive guide breaks down the technical specs, image dimensions, file limits, and text constraints for LinkedIn’s most powerful ad formats.

1. Single Image Ads

The workhorse of B2B lead generation, single-image ads appear directly in the user’s feed and support three distinct aspect ratios.

| Treatment | Recommended Size | Aspect Ratio | Delivery | Max File Size / Format |
| :— | :— | :— | :— | :— |
| Landscape | 1200 × 628 px | 1.91:1 | Desktop & Mobile | 5 MB (JPG, PNG, GIF) |
| Square | 1200 × 1200 px | 1:1 | Desktop & Mobile | 5 MB (JPG, PNG, GIF) |
| Vertical | 720 × 900 px | 4:5 | Mobile Only | 5 MB (JPG, PNG, GIF) |

• Introductory Text: 150 characters recommended to avoid truncation on mobile (hard maximum: 600 characters).
• Headline: 70 characters recommended to prevent cutoff (maximum: 200 characters).
• Description: 70 characters or less recommended.

2. Video Ads

Video is essential for capturing attention in a fast-moving professional feed. Because a massive portion of LinkedIn users watch content on mute, burned-in or uploaded SRT caption files are non-negotiable.

• File Type: MP4
• File Size: 75 KB (min) to 500 MB (max)
• Duration: 3 seconds to 30 minutes (15 to 30 seconds perform best for brand awareness).
• Frame Rate: 30 FPS or less.

Aspect Ratios & Resolutions:

• Landscape (16:9): 1920 × 1080 px
• Square (1:1): 1920 × 1920 px
• Vertical (4:5): 1080 × 1350 px (Recommended for mobile feeds)
• Vertical (9:16): 1080 × 1920 px

3. Carousel Ads

Carousels allow you to tell a sequential brand story, highlight multi-feature product rollouts, or break down data points step-by-step.

• Card Count: 2 to 10 cards per ad
• Image Size: 1080 × 1080 pixels (1:1 aspect ratio)
• Max File Size: 10 MB per card (Supported: JPG, PNG, non-animated GIF).
• Card Headline: 45 characters max (if linking to a destination URL).
• Introductory Text: Up to 150 characters recommended to dodge mobile truncation (maximum: 255 characters).

4. Document Ads

If you are gating a high-value whitepaper, research report, or slide deck, Document Ads let users swipe through the content natively inside the LinkedIn feed without forcing an immediate redirect.

• File Formats: PDF, DOC, DOCX, PPT, PPTX
• Max File Size: 100 MB
• Page Limit: Up to 300 pages (optimal engagement typically sits between 5 to 15 pages).
• Orientation: Vertical, horizontal, or square documents are all supported.

5. Message Ads & Conversation Ads

Direct-to-inbox advertising targets decision-makers right where they manage priority correspondence.

• Sender Image: 250 × 250 px (Square profile photo of a real company leader or sender).
• Message Text: Up to 1,500 characters (shorter messages generally yield higher click-through rates).
• Custom Footer / Terms & Conditions: Up to 20,000 characters.
• Call-to-Action (CTA) Button: Up to 20 characters.
• Companion Banner (Desktop Only): 300 × 250 px (JPG or PNG, max 2 MB). Note: Conversation ads add dynamic, multi-path branching options to this format.

6. Dynamic Ads (Follower & Spotlight Ads)

Dynamic ads automatically personalize themselves using the target user’s profile data (such as their first name, company name, or profile photo).

• Company Logo / Image: 100 × 100 px (JPG or PNG, max 2 MB).
• Headline / Description: Up to 50 characters for Spotlight headlines; 70 characters for descriptions.
• Background Image (Spotlight Ads only): 300 × 250 px.

Pro-Tips for LinkedIn Ad Success

1. Design for Mobile First: Over 60% of LinkedIn traffic originates on mobile devices. Utilizing square (1:1) or vertical (4:5) formats grabs significantly more screen real estate than landscape alternatives.
2. Stick to sRGB Color Space: When exporting graphics from design suites like Adobe Photoshop or Illustrator, always verify your color profile is set to sRGB to prevent washed-out colors upon upload.
3. Front-Load Your Copy: Because LinkedIn truncates mobile introductory text past 150 characters, ensure your core value proposition, hook, or primary statistic sits safely within the first two lines.