Wrong aspect ratio = cropped persona, cut-off captions, lost reach. For an AI influencer that posts dozens of times per day across platforms, the aspect ratio decision is automated by the orchestration layer — but the table behind that automation has to be correct.
This is the 2026 cheat sheet: every major platform, every content format an AI influencer ships, with image generation specs for both GPT-Image-2 and Nano Banana Pro.
Quick Reference Table
| Platform | Format | Aspect Ratio | Pixels | GPT-Image-2 | Nano Banana Pro | |---|---|---|---|---|---| | Instagram | Feed (square) | 1:1 | 1080×1080 | 2K @ 1:1 | 2K @ 1:1 | | Instagram | Feed (portrait) | 4:5 | 1080×1350 | 2K @ 4:3 (crop) | Native 4:5 not listed; use 4:3 | | Instagram | Reels / Stories | 9:16 | 1080×1920 | 2K @ 9:16 | 2K @ 9:16 | | TikTok | Video / Image post | 9:16 | 1080×1920 | 2K @ 9:16 | 2K @ 9:16 | | X (Twitter) | Feed image (landscape) | 16:9 | 1600×900 | 2K @ 16:9 | 2K @ 16:9 | | X (Twitter) | Single image (square) | 1:1 | 1200×1200 | 2K @ 1:1 | 2K @ 1:1 | | YouTube | Thumbnail | 16:9 | 1920×1080 | 2K @ 16:9 | 2K @ 16:9 | | YouTube | Shorts | 9:16 | 1080×1920 | 2K @ 9:16 | 2K @ 9:16 | | LinkedIn | Feed link card | 1.91:1 | 1200×627 | 2K @ 16:9 (crop) | Native 1.85:1 | | LinkedIn | Square post | 1:1 | 1080×1080 | 2K @ 1:1 | 2K @ 1:1 | | Pinterest | Standard pin | 2:3 | 1000×1500 | 2K @ 3:4 (crop) | 2K @ 3:4 (crop) | | Pinterest | Long pin | 1:2.1 | 1000×2100 | 2K @ 9:16 (crop) | 2K @ 1:4 (native) | | Facebook | Feed image | 1.91:1 | 1200×630 | 2K @ 16:9 | Native 1.85:1 | | Threads | Feed image | 1:1 or 9:16 | 1080×1080 / 1080×1920 | 2K @ 1:1 or 9:16 | 2K @ 1:1 or 9:16 | | Telegram | Inline preview | 16:9 | 1280×720 | 2K @ 16:9 | 2K @ 16:9 | | Cinematic banner | Hero / cover | 2.39:1 | 2400×1000 | Not native (crop 16:9) | Native 2.39:1 |
Nano Banana Pro's broader aspect ratio coverage (5:3, 1.85:1, 2.39:1, 4:1, 1:4) is the technical edge for cinematic and ultra-wide content. For standard social platforms, GPT-Image-2's six options cover everything.
Platform-by-Platform Breakdown
The dominant platform for AI influencer content. Three feed formats:
- 1:1 (square) — safe default, never gets cropped
- 4:5 (portrait) — takes more screen real estate, ~30% higher engagement
- 9:16 (Reels / Stories) — full-screen vertical, mandatory for short-form video and UGC video clips
For an AI influencer's daily lifestyle feed, 4:5 wins on engagement. For carousels, lock all slides at 1:1 to keep the swipe experience consistent.
TikTok
Single ratio: 9:16. Anything else gets letterboxed and the algorithm punishes letterboxing. For static "TikTok Photos" posts, still 9:16.
UGC-style video frames generated for TikTok should be at 1080×1920 minimum, generated 9:16 native — not cropped from 1:1.
X (Twitter)
Two viable options:
- 16:9 (1600×900) — landscape lifestyle posts, screenshots, link images
- 1:1 (1200×1200) — square portraits, quote graphics
X crops aggressively in feed previews but expands on click. Keep persona face and any text inside the center 60% of the canvas to survive the crop.
YouTube
- Thumbnails: 16:9 at 1920×1080. The persona's face should occupy at least 25% of the canvas, eyes near the upper third. Text must be readable at 320×180.
- Shorts: 9:16. Mandatory for the Shorts shelf — required for influencer agents pushing short-form video content.
- 1.91:1 (1200×627) for link previews
- 1:1 (1080×1080) for native image posts — gets ~25% more reach
LinkedIn's algorithm favors square posts because they take more vertical screen space. For B2B AI influencers, 1:1 is the default.
Pinterest is the only major platform where portrait dominates:
- 2:3 (1000×1500) — standard pin
- 1:2.1 (1000×2100) — long pins, great for infographics, drop announcements, multi-product posts
Anything wider than 2:3 gets demoted. Nano Banana Pro's native 1:4 ratio is well-suited for ultra-long pins; GPT-Image-2 users should generate at 9:16 and crop the top/bottom.
Telegram
For AI influencer content distributed via Telegram channels and bots:
- Inline link previews: 16:9 at 1280×720
- Channel posts: 1:1 or 9:16
Facebook & Threads
Facebook: 1.91:1 for link previews, 1:1 for image posts. Threads: matches Instagram — 1:1 or 9:16.
AI Generation Specs by Model
GPT-Image-2
Supported aspect ratios: 1:1, 9:16, 16:9, 4:3, 3:4, auto
Always specify the ratio explicitly — auto-mode caps at 1K resolution, which is too low for thumbnails or premium UGC video frames. Use 2K for production, 4K only when the content will be repurposed for print or display advertising.
Nano Banana Pro
Supported aspect ratios: 1:1, 4:3, 5:3, 9:16, 1.85:1 (cinematic), 2.39:1 (anamorphic), 2.75:1, 4:1, 1:4
Broader coverage than GPT-Image-2. Useful for cinematic banner assets, ultra-wide LinkedIn header content, vertical sidebar ads, and Pinterest long pins.
For routing logic in an AI influencer pipeline, see GPT-Image-2 vs Nano Banana Pro.
The Center 60% Rule (Cropping Survival)
Every platform crops differently in feed previews. Survival rule for AI influencer content: keep the persona's face and any caption text inside the center 60% of the canvas, and well inside the center 80% vertically.
That way, regardless of which platform reposts or how it auto-crops, the content survives — same face recognizable in feed thumbnails, captions readable in preview, no awkward decapitations.
For UGC video frames specifically: pose mid-canvas, reaction reactions framed in upper-third, hands and props in lower-third. The same composition rules photographers use apply.
Multi-Platform Strategy for AI Influencers
Three approaches, ranked by effort and result:
- One-size-fits-all (low effort, low return) — generate 1:1, accept that Reels and Pinterest underperform.
- Two-format default (medium effort, high return) — generate 1:1 and 9:16 for every post. Covers ~85% of platform value.
- Platform-native (high effort, highest return) — generate the exact aspect ratio per platform. Best engagement, requires orchestration.
For AI influencer pipelines, platform-native is the right answer because it's automatable. Once the pipeline knows which platforms the agent posts to, it can request the correct ratio per generation without human intervention. OmniGems AI handles this routing automatically — the creator picks the platforms; the platform picks the ratios.
FAQ
What's the safest single aspect ratio for an AI influencer?
1:1. It works everywhere without dramatic cropping, just lower engagement than platform-native ratios.
Does aspect ratio actually affect reach for AI agents?
Yes — same as for human influencers. Algorithms reward content that uses the platform's preferred ratio because it occupies more screen and increases dwell time. Instagram 4:5 typically shows 20–30% engagement lift over 1:1.
Should I use Nano Banana Pro just for the wider aspect ratio coverage?
Only for cinematic / ultra-wide content. For standard social posts (1:1, 9:16, 16:9), GPT-Image-2 covers everything and is faster. See the full comparison.
What about 4K resolution?
Use 4K when the content gets repurposed for display ads, print, or large-format video. For social feed posts, 2K is enough — platforms re-compress on upload anyway.
How do I generate UGC video frames?
Generate the still at 9:16 / 2K with a strong UGC aesthetic prompt (phone flash, motion blur, mixed color temperature), then animate via the UGC video pipeline. See How AI Agents Post on Social Media for the full content flow.
Ship to Every Platform
Aspect ratio is the difference between an AI influencer post that fills the screen and one that gets cropped to nothing. Pick the right ratio per platform, generate at 2K, keep the persona's face centered.
For multi-platform AI influencer content with automated ratio routing, try OmniGems AI Studio — the platform handles the per-platform sizing so the agent ships the right format every time.