The Ultimate Guide to LinkedIn Paid Ad Specs

Running campaigns on LinkedIn is a powerful play for B2B marketers, enterprise sellers, and recruiters. But unlike platforms where creative assets can easily flex across placements, LinkedIn has zero tolerance for sloppy exports. A single misaligned pixel ratio or an exceeded file size limit can stall your campaign deployment or cause your visuals to crop awkwardly in a professional’s feed.

This comprehensive guide breaks down the technical specifications, creative dimensions, and copy caps for LinkedIn’s core paid ad formats to ensure your campaigns launch smoothly and look sharp.

1. Single Image Ads

Single image ads appear directly in the LinkedIn feed, serving as the workhorse for brand awareness, lead generation, and content promotion. Because they render across both desktop and mobile feeds, picking the right aspect ratio is crucial.

• Landscape (Desktop & Mobile):
  • Recommended Size: $1200 times 628$ pixels ($1.91:1$ ratio)
  • Minimum Size: $640 times 360$ pixels
• Square (Desktop & Mobile):
  • Recommended Size: $1200 times 1200$ pixels ($1:1$ ratio)
  • Minimum Size: $360 times 360$ pixels
• Vertical (Mobile Only):
  • Recommended Size: $720 times 900$ pixels ($4:5$ ratio)
  • Note: Vertical images occupy more mobile screen real estate, boosting thumb-stop rates, but they will not display on desktop feeds.
• Technical Limits:
  • File Formats: JPG, PNG, or non-animated GIF
  • Max File Size: 5 MB

2. Video Ads

Video on LinkedIn is a primary driver for deep engagement, product walkthroughs, and thought leadership. Since feeds auto-play videos silently by default, captions are non-negotiable.

• Aspect Ratios & Resolutions:
  • Landscape (16:9): $1920 times 1080$ pixels
  • Square (1:1): Up to $1920 times 1920$ pixels
  • Vertical (4:5): $720 times 900$ pixels recommended
  • Vertical (9:16): Up to $1080 times 1920$ pixels
• Technical Limits:
  • File Format: MP4
  • Codec: H.264 or VP8
  • File Size: 75 KB to 500 MB
  • Duration: 3 seconds to 30 minutes (15 to 30 seconds is the sweet spot for conversion)
  • Frame Rate: Up to 30 fps

Pro Tip: Always upload a custom thumbnail (JPG or PNG, matching your video’s aspect ratio and capped at 2 MB) rather than letting LinkedIn pull a random auto-frame.

3. Carousel Ads

Carousel ads allow you to tell a sequential story, showcase a product feature set, or share step-by-step insights across multiple swipeable cards.

• Card Count: 2 to 10 cards per ad
• Image Dimensions: $1080 times 1080$ pixels ($1:1$ aspect ratio)
• File Formats: JPG, PNG, or non-animated GIF
• Max File Size: 10 MB per card

4. Document Ads

If you are gating whitepapers, heavy industry reports, or cheat sheets directly inside the feed without forcing a landing page click, Document Ads are your go-to format.

• File Formats: PDF, PPT, PPTX, DOC, or DOCX
• Max File Size: 100 MB
• Page Limit: Up to 300 pages

5. Text, Spotlight, and Message Ads

Right-rail and messaging options provide alternative touchpoints outside the standard content feed.

| Format | Core Asset Size / Spec | File Limit |
| :— | :— | :— |
| Text Ads | $100 times 100$ px company logo | JPG or PNG, max 2 MB |
| Spotlight Ads | $100 times 100$ px logo + optional $300 times 250$ px background image | JPG or PNG, max 2 MB |
| Conversation Ads | Optional desktop companion banner at $300 times 250$ px | JPG or PNG, max 2 MB |

Copy Constraints Cheat Sheet

Designing the visual is only half the battle. LinkedIn strictly enforces character limits on text elements. Exceeding them results in hard truncation:

• Single Image Intro Text: 150 characters (optimal for avoiding “see more” cutoff)
• Single Image Headline: 70 characters
• Carousel Card Headline: 45 characters
• Text Ad Headline: 25 characters
• Text Ad Description: 75 characters
• Spotlight Ad Headline: 50 characters
• Lead Gen Form Call-to-Action (CTA): 20 characters

Summary Checklist for Campaign Success

Before submitting your assets to Campaign Manager, run through this quick quality assurance checklist:

1. Match your aspect ratios: Use $1:1$ or $4:5$ for mobile-heavy feed placements to maximize visual presence.
2. Double-check copy lengths: Keep your core hooks well within the character caps to prevent clumsy ellipses.
3. Embed hard subtitles on videos: Assume every user scrolls with sound off until proven otherwise.

By aligning your creative assets precisely with these specifications, you will protect your media budget from rendering glitches and keep your professional audience focused entirely on your message.