Ad Platform Specs
LinkedIn Ads Specs
LinkedIn ads are expensive enough that spec mistakes are costly. These are the formats I use most, with the character limits that determine whether your headline reads as a sentence or a fragment on mobile.
| Element | Specification |
|---|---|
| Recommended ratios | 1.91:1, 1:1 and 4:5 |
| Recommended pixels | 1200 x 627, 1080 x 1080 or 1080 x 1350 |
| Introductory text | Around 150 characters before truncation |
| Headline | Around 70 characters recommended |
| File types | JPG, PNG or GIF, non animated |
| Format | Key specifications |
|---|---|
| Video ad | 16:9, 1:1 or 9:16, MP4, captions recommended |
| Carousel ad | 2 to 10 cards, 1:1 at 1080 x 1080 |
| Carousel card headline | Around 45 characters |
| Document ad | PDF, DOC, DOCX, PPT or PPTX, up to 10 pages shown |
| Conversation and message ads | Availability varies by region and regulation |
| Item | Guidance |
|---|---|
| Minimum audience size | 300 members required to deliver |
| Recommended audience size | 50,000 or more for most objectives |
| Frequency management | Rotate creative every 2 to 4 weeks |
Notes
Document ads are the format most under used relative to how well they perform for B2B lead capture. A ten page PDF that delivers real value in the preview and gates only the deeper version converts far better than a generic ebook landing page.
LinkedIn audiences fatigue quickly because the addressable pool is small and professional targeting narrows it further. If frequency climbs past roughly three to four impressions per member per week, expect click through rate to fall regardless of creative quality. Refresh creative on a calendar, not on a performance trigger.
Message ads are restricted or unavailable in several jurisdictions for regulatory reasons, and the rules change. Verify availability for your target geographies inside Campaign Manager before planning a program around the format.
LinkedIn revises ad format specs and recommended lengths regularly, and Campaign Manager itself shows the current values at build time. Trust the in product guidance and LinkedIn's own help pages over any cached table.
Frequently asked questions
What is the minimum LinkedIn audience size?
300 members is the technical minimum for a campaign to serve. In practice, anything under a few thousand delivers erratically and at high cost.
Are LinkedIn lead gen forms worth it?
Usually yes for top of funnel. They pre fill from the profile, which lifts conversion rate sharply, at the cost of lead intent. Route them into nurture rather than straight to sales.
Official sources
Platforms change specifications without notice. Check the primary documentation before a launch that depends on an exact value.
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