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LinkedIn Ad Specs and Sizes 2026: Complete Cheat Sheet by Format
LinkedIn ad specs for 2026: Single image ads support 1200×627 (1.91:1 landscape), 1200×1200 (1:1 square), or 720×900 (4:5 vertical). Video ads support 1920×1080 (16:9), 1080×1080 (1:1), or 1080×1350 (4:5) with max 200MB and 30 minutes. Carousel cards are 1080×1080 with 2-10 cards. Headlines limit at 70 characters; intro text at 600 (mobile shows ~150). The recommended default for B2B SaaS is 1200×1200 square — it occupies more mobile screen space than landscape and delivers 30-60% higher CTR than 4:5 vertical.
Key Takeaways
- The default recommended LinkedIn ad size for B2B SaaS is 1200×1200 (1:1 square) — best mobile visibility and consistent cross-device delivery.
- Vertical 4:5 ads (720×900) deliver only to mobile devices — never use vertical if your audience is desktop-heavy.
- Video ads cap at 200MB and 30 minutes; 15-30 second videos perform best for awareness, 60-90 seconds for consideration.
- All single-image LinkedIn ads max out at 5MB file size; videos at 200MB; documents at 100MB.
- Image text overlay must stay below 20% — LinkedIn adopted Meta’s former 20% rule in 2025 and now auto-rejects violators.
- Carousel ads support 2-10 cards at 1080×1080 each; 4-6 cards produce the highest engagement.
The Complete LinkedIn Ad Specs Table
Bookmark this table for quick reference. Every LinkedIn ad format with dimensions, aspect ratios, file limits, and character constraints for 2026:
| Format | Recommended Size | Aspect Ratio | File Type | Max File Size | Notes |
|---|---|---|---|---|---|
| Single Image (Landscape) | 1200×627 | 1.91:1 | JPG, PNG, GIF | 5MB | Traditional default |
| Single Image (Square) | 1200×1200 | 1:1 | JPG, PNG, GIF | 5MB | Recommended default |
| Single Image (Vertical) | 720×900 | 4:5 | JPG, PNG, GIF | 5MB | Mobile-only delivery |
| Carousel Ads | 1080×1080 per card | 1:1 | JPG, PNG | 10MB per card | 2-10 cards per ad |
| Video (Landscape) | 1920×1080 | 16:9 | MP4 | 200MB | Standard widescreen |
| Video (Square) | 1080×1080 | 1:1 | MP4 | 200MB | Best mobile visibility |
| Video (Vertical) | 1080×1350 | 4:5 | MP4 | 200MB | Mobile-only delivery |
| Video (Full Vertical) | 1080×1920 | 9:16 | MP4 | 200MB | Mobile-only delivery |
| Document Ads | N/A (PDF, PPT, DOC) | N/A | PDF, PPT, DOC | 100MB | 8-12 pages optimal |
| Thought Leader Ads | Inherits organic post | Various | Various | Same as post | Sponsors organic content |
| Text Ads | 100×100 thumbnail | 1:1 | JPG, PNG | 2MB | Desktop-only |
| Message Ads | Sender photo | N/A | N/A | N/A | No image required |
| Conversation Ads | Sender photo | N/A | N/A | N/A | No image required |
| Connected TV Ads | 1920×1080 | 16:9 | MP4 | 500MB | 6-30 seconds |
| Spotlight Ads | 100×100 logo | 1:1 | JPG, PNG | 2MB | Desktop right rail |
For character limits across all formats, see LinkedIn Ad Copy Best Practices — the companion piece to this spec sheet.
Single Image Ads: Pick the Right Aspect Ratio
Single image ads support 3 aspect ratios, and the choice affects delivery, screen real estate, and CTR significantly:
1200×627 (1.91:1 Landscape)
The traditional default. Works across all devices. Takes up less mobile screen space than square or vertical formats. Best for ads designed for desktop-heavy audiences (older B2B audiences, IT teams, healthcare IT, fintech).
- Use when: desktop traffic is significant; design fits widescreen composition; you have legacy creative built for this ratio
- CTR baseline: 0.44-0.56% median for B2B SaaS
1200×1200 (1:1 Square) — Recommended Default
The best balance of cross-device delivery and mobile visibility. Square images occupy 60% more mobile screen space than landscape — visibility translates to CTR. Recommended as the default LinkedIn ad size for most B2B SaaS campaigns in 2026.
- Use when: you don’t have a strong reason to use landscape or vertical
- CTR baseline: 0.50-0.70% median for B2B SaaS (30-60% higher than landscape on mobile-heavy audiences)
720×900 (4:5 Vertical)
Critical limitation: vertical ads deliver only to mobile devices. If your campaign targets desktop-heavy audiences (procurement, IT operations, certain enterprise verticals), vertical ads will under-deliver dramatically.
- Use when: audience is 80%+ mobile and you want maximum scroll real estate
- Avoid when: desktop traffic is meaningful (most B2B SaaS campaigns)
- CTR baseline: Mobile-only metric — not directly comparable to square or landscape
Video Ad Specs
LinkedIn video ads support four aspect ratios with strict file requirements:
Technical requirements (all video formats):
- File format: MP4 (required) with H.264 codec
- Maximum file size: 200MB
- Frame rate: 30 fps (recommended)
- Bitrate: 5-10 Mbps
- Audio: AAC or MP3, 64-128 kbps
- Minimum resolution: 720p (1280×720)
Duration guidance by objective:
| Objective | Optimal Length | Notes |
|---|---|---|
| Brand Awareness | 6-15 seconds | Front-load the hook |
| Video Views (viewer audience building) | 30-60 seconds | Enough time to filter intent |
| Consideration / Engagement | 60-90 seconds | Detail without losing attention |
| Conversion campaigns | 15-30 seconds | Direct CTA at end |
| Maximum allowed | 30 minutes | Almost never beneficial |
Videos under 30 seconds maintain 60%+ completion rates. Videos over 60 seconds drop to 20-30% completion. The sweet spot for most B2B SaaS use cases is 15-30 seconds for direct response, 60-90 seconds for thought leadership content.
Aspect ratio guidance (video):
- 16:9 (1920×1080): Standard widescreen, all devices. Best for landscape video content (interviews, product demos).
- 1:1 (1080×1080): Square format, all devices. Recommended default — same mobile-visibility advantage as square static.
- 4:5 (1080×1350): Vertical, mobile-only. Use when audience is heavily mobile.
- 9:16 (1080×1920): Full vertical, mobile-only. Maximum mobile screen real estate.
All non-9:16 vertical videos deliver to both mobile and desktop. Only 4:5 and 9:16 are mobile-only.
Carousel Ad Specs
Carousel ads support 2-10 cards per ad. Each card is a separate creative with its own image, headline, and destination URL.
Specs:
- Card size: 1080×1080 minimum (1:1 aspect ratio)
- Number of cards: 2-10 (recommended: 4-6)
- File size per card: 10MB max
- Headline per card: 45 characters max
- Description per card: 30 characters max
- Each card can link to a different URL
Design guidance:
- First card must hook attention. If users don’t swipe past card 1, the entire carousel underperforms. Lead with the strongest visual or value-prop.
- 4-6 cards is the sweet spot. Below 4: doesn’t justify the carousel format. Above 7: completion rates drop sharply.
- Last card should have a CTA. Many users swipe to the end before deciding to act.
Carousel ads achieve 2x the CTR of single-image ads at similar CPC, making them one of the highest-leverage formats when used correctly.
Document Ad Specs
Document Ads display PDFs natively in the LinkedIn feed. Users can preview 2-3 pages before being prompted to fill a Lead Gen Form for the full download.
Specs:
- File format: PDF (preferred), PPT, PPTX, DOC, DOCX
- Max file size: 100MB
- Optimal length: 8-12 pages
- Page dimensions: Standard letter (8.5×11) or A4 — both render correctly
Design rules:
- Page 1 must hook in 2 seconds. Bold headline + hero metric + clear “what’s inside” preview. No generic “cover” pages with company logos.
- 8-12 pages is optimal. Below 6 pages: not enough value to justify the swipe investment. Above 15: completion rates collapse.
- Each page must deliver substantive content. LinkedIn users abandon documents that pad with thin content.
Document Ads achieve a 22.73% form completion rate — the highest of any LinkedIn ad format — when content quality matches the headline promise.
Character Limits Across Ad Formats
Quick reference for character limits (full breakdown in the Ad Copy Best Practices guide):
| Element | Max | Practical Limit |
|---|---|---|
| Headline (Single Image, Video, Document) | 70 | 50-65 |
| Introductory text | 600 | 150 (mobile preview) |
| Description text | 70 | 50-65 |
| Carousel headline per card | 45 | 30-40 |
| Carousel description per card | 30 | 20-25 |
| CTA button | 10 | Preset options |
| Lead Gen Form headline | 60 | 40-55 |
| Lead Gen Form details | 160 | 120-140 |
| Conversation Ad subject | 60 | 30-50 |
| Message Ad subject | 60 | 30-50 |
| Text Ad headline | 25 | 20-25 |
| Text Ad description | 75 | 60-70 |
The 2026 Compliance Rules Affecting Specs
LinkedIn updated its ad creative policies in early 2026. Three rules now apply to image specs:
1. 20% text-overlay rule. Images with more than 20% text overlay trigger automatic rejection. Use LinkedIn’s mockup tool to check before launch.
2. Stock photo restrictions. LinkedIn’s AI now flags obvious stock imagery and penalizes delivery (not outright rejection — just lower auction priority). Use authentic photos when possible.
3. Faces lift engagement. Ads featuring real people (not stock models) increase engagement by 20-30%. LinkedIn’s algorithm appears to prefer faces in ad creative, though the company hasn’t confirmed this officially.
Common Spec Mistakes
Mistake 1: Using 4:5 vertical ads for desktop-heavy audiences. Vertical only delivers to mobile. If you target desktop-dominant audiences (procurement, IT ops), your delivery collapses.
Mistake 2: Saving images with aggressive JPG compression. Compression artifacts make ads look unprofessional and lower auction relevance scores. Export at 80%+ quality.
Mistake 3: Uploading images below recommended dimensions. LinkedIn upscales smaller images, which creates pixelation. Always upload at the recommended size or larger.
Mistake 4: Letting carousel cards exceed 7. Above 7 cards, completion rates drop dramatically. Stick to 4-6 for most B2B SaaS use cases.
Mistake 5: Putting more than 20% text on images. This triggers automatic rejection in 2026. Check with the mockup tool before launch.
Mistake 6: Using outdated 1200×627 (1.91:1) as the default. This was the standard for years but is now the worst choice for mobile-heavy audiences. Switch to 1200×1200 (1:1) as your default.
Recommended Defaults by Use Case
Skip the spec table for common scenarios — here’s what to use:
| Use Case | Recommended Spec |
|---|---|
| Default Sponsored Content | 1200×1200 (1:1 square) |
| Mobile-first awareness campaign | 720×900 (4:5) or 1080×1920 (9:16) video |
| Desktop-heavy audience | 1200×627 (1.91:1) or 1200×1200 (1:1) |
| Brand video ad | 1080×1080 (1:1) video, 30 seconds |
| Demo / product video | 1920×1080 (16:9) video, 60-90 seconds |
| Carousel storytelling | 4-6 cards at 1080×1080 |
| Gated content offer | Document Ad, 8-12 pages |
| Thought Leader Ad amplification | Inherit organic post specs |
How OLA Optimizes Around Your Creative Specs
OLA doesn’t design your creative — that’s a creative discipline. But OLA does:
- Surface creative fatigue alerts when CTR drops 30%+ over 2 weeks (signal to refresh)
- Track CTR by format and aspect ratio across all your campaigns
- Identify which ad sizes are top-performing for your specific audience
- Apply company-level frequency caps so creative doesn’t get over-exposed
Flat $29/month. 15-minute OAuth setup. Works for B2B SaaS teams running $5K–$100K/month in LinkedIn spend.
For teams that want senior operators handling creative production, A/B testing, and weekly refresh cycles, GrowthSpree’s managed service wraps OLA into a $3,000/month flat engagement — month-to-month, HubSpot-native.
FAQs
What’s the best LinkedIn ad size?
The best LinkedIn ad size for most B2B SaaS campaigns is 1200×1200 pixels (1:1 square). Square ads occupy more mobile screen space than landscape (1200×627), which translates to 30-60% higher CTR. Use 4:5 vertical (720×900) only if your audience is 80%+ mobile — vertical ads don’t deliver on desktop.
What’s the LinkedIn ad image size in 2026?
LinkedIn supports three single-image ad sizes in 2026: 1200×627 (1.91:1 landscape), 1200×1200 (1:1 square), or 720×900 (4:5 vertical). Maximum file size is 5MB. JPG, PNG, and GIF formats supported. Recommended default for B2B SaaS is 1200×1200 square.
What’s the max video size for LinkedIn ads?
LinkedIn video ads have a 200MB maximum file size (vs 5GB for organic native video). Format must be MP4 with H.264 codec. Maximum duration is 30 minutes, though 15-30 seconds performs best for direct response and 60-90 seconds for thought leadership content.
What aspect ratios does LinkedIn support for video?
LinkedIn supports four video aspect ratios: 16:9 (1920×1080) landscape, 1:1 (1080×1080) square, 4:5 (1080×1350) vertical, and 9:16 (1080×1920) full vertical. Square (1:1) is the recommended default for most B2B SaaS. 4:5 and 9:16 are mobile-only — they won’t deliver to desktop users.
How many cards can a LinkedIn carousel ad have?
LinkedIn carousel ads support 2-10 cards per ad. The optimal range is 4-6 cards — below 4 doesn’t justify the carousel format; above 7 sees completion rates drop sharply. Each card is 1080×1080 pixels with separate headline (45 chars), description (30 chars), and destination URL.
Why was my LinkedIn ad rejected for text overlay?
LinkedIn adopted the 20% text-overlay rule in 2025. Ads with more than 20% of the image area covered by text trigger automatic rejection. Use LinkedIn’s mockup tool to check text coverage before launch. If your design needs more text, move it to the headline or intro text fields instead.
What’s the optimal length for a LinkedIn video ad?
For B2B SaaS, 15-30 seconds is optimal for direct response (demo requests, trials, downloads). 60-90 seconds is optimal for thought leadership and product explainer content. Videos under 30 seconds maintain 60%+ completion rates; videos over 60 seconds drop to 20-30% completion. Front-load the hook in the first 3 seconds regardless of length.
Should I use landscape or square LinkedIn ads?
Square (1200×1200) is the recommended default for most B2B SaaS in 2026. Square ads occupy 60% more mobile screen space than landscape (1200×627), which translates to 30-60% higher CTR on mobile-heavy audiences. Use landscape only when your design genuinely requires widescreen composition or your audience is predominantly desktop.
Build Better Creative with Real Performance Data
Connect OLA and see CTR by aspect ratio, format, and creative variant across your account. Most teams discover their best-performing ad format is delivering 3x the engagement of their default — but they’re still running their old defaults.
