- 4K Quality: Supports 1K, 2K, 4K resolutions
- Ultra Intelligent: Based on Gemini 3 architecture, precise understanding of complex prompts
- Best Value: Only **0.09/image∗∗(62.50.09/image** (62.5% cheaper than official 0.09/image∗∗(62.50.24)
🎁 Free Trial
Register and get $0.5 credit toward Nano Banana Pro usage🚀 Live Demo
AI Images - Try instantly, no code requiredPrerequisites
1 Get API Key Login to YeLIn AI console to get your API key 2 Configure Billing Mode Edit token settings and select one of these billing modes (same price):- Pay-per-use Priority (Recommended): Use balance first, auto-switch when insufficient. Best for most users
- Pay-per-use: Direct charge per request. Best for strict budget control
请在 Console 查看对应界面截图。
Model Overview
Nano Banana Pro is LaoZhang API’s custom name for Google’s Gemini 3 Pro Image Preview (gemini-3-pro-image-preview) model. Designed for professional use cases requiring ultimate image quality and complex semantic understanding.
Core Advantages
- 🌟 Native 4K Resolution: Generate up to 4096×4096 ultra-high-definition images.
- 🧠 Gemini 3 Intelligence: Built-in logical reasoning, understands abstract descriptions like “a cat looking at an empty bowl with disappointment after missing breakfast”.
- 💪 Complex Composition: Precise control over object placement, quantity, and text rendering.
- 💰 Best Price: $0.09/image for premium image generation use cases.
🌟 Core Features
- ⚡ Fast Response: ~10 seconds average, significantly faster than OpenAI series
- 💰 Great Value: 0.09/image(62.50.09/image (62.5% cheaper than official 0.09/image(62.50.24)
- 🔄 Dual Compatibility: Supports OpenAI SDK and Google native formats
- 📐 Flexible Sizes: Google native format supports 10 aspect ratios
- 🖼️ High Resolution: Supports 1K, 2K, 4K resolutions
- 🧠 Thinking Mode: Built-in reasoning process, optimizes composition before generation (enabled by default)
- 🌐 Search Grounding: Supports Google Search for fact verification and image generation
- 🎨 Multi-Image Reference: Supports up to 14 reference images (6 objects + 5 characters, etc.)
- 📦 Base64 Output: Returns base64 encoded image data directly, no secondary download needed
🔀 Two API Modes
Nano Banana Pro supports two endpoints, each with unique advantages:| Feature | OpenAI Compatible Mode | Google Native Format |
|---|---|---|
| Endpoint | /v1/chat/completions | /v1beta/models/gemini-3-pro-image-preview:generateContent |
| Model Name | gemini-3-pro-image-preview | Specified in URL |
| Image Size | Fixed 1:1 | 10 aspect ratios |
| Resolution | Fixed 1K | 1K/2K/4K |
| Compatibility | Perfect with OpenAI SDK | Requires native calls |
| Return Format | Base64 | Base64 |
| Use Case | Quick migration, simple needs | Custom sizes or high resolution |
- For square (1:1) images only, use OpenAI Compatible Mode - simpler
- For widescreen (16:9), portrait (9:16), or other specific ratios or high-res (2K/4K), use Google Native Format
📋 Model Comparison
Comparison with Other Image Models
| Model | Model ID | Billing | LaoZhang API Price | Official Price | Savings | Resolution | Speed |
|---|---|---|---|---|---|---|---|
| Nano Banana Pro | gemini-3-pro-image-preview | Per-use | $0.09/image | $0.24/image | 62.5% | 1K/2K/4K | ~10s |
| Nano Banana2 | gemini-3.1-flash-image-preview | Per-use | $0.055/image | - | - | 1K/2K/4K | ~10s |
| Nano Banana | gemini-2.5-flash-image | Per-use | $0.025/image | $0.04/image | 37.5% | 1K (fixed) | ~10s |
| GPT-Image-1 | gpt-image-1 | Token-based | 10input/10 input/10input/40 output per M | - | - | - | Medium |
| Flux Kontext Pro | flux-kontext-pro | Per-use | $0.035/image | $0.04/image | 12.5% | - | Fast |
| Sora Image | sora_image | Per-use | $0.01/image | - | - | - | Slower |
- Nano Banana Pro: 0.09/image(LaoZhangAPI)vs0.09/image (LaoZhang API) vs 0.09/image(LaoZhangAPI)vs0.24/image (official), 62.5% cheaper
- Bonus: Get +10% bonus on large deposits
- Exchange Rate: Paying in CNY is even more cost-effective
🚀 Quick Start
Prerequisites
1 Create Token Login to LaoZhang API Token Management and create a pay-per-use type token(截图请在 Console 查看) 2 Select Billing Type Important: Must select “Pay-per-use” type, not “Pay-as-you-go” 3 Save Token Copy the generated token in formatsk-xxxxxx
Method 1: OpenAI Compatible Mode (1:1 Images)
Best for quick integration, generates 1024x1024 (1K) images by default.Basic Example - Curl
Python SDK Example
Method 2: Google Native Format (Custom Aspect Ratio + 4K)
Best for 4K resolution or custom aspect ratio needs.Supported Aspect Ratios
| Type | Aspect Ratio Options |
|---|---|
| Landscape | 21:9 (Ultra-wide), 16:9 (Widescreen), 4:3, 3:2 |
| Square | 1:1 |
| Portrait | 9:16 (Vertical), 3:4, 2:3 |
| Other | 5:4, 4:5 |
Supported Resolutions
| Aspect Ratio | 1K Resolution | 2K Resolution | 4K Resolution |
|---|---|---|---|
| 1:1 | 1024×1024 | 2048×2048 | 4096×4096 |
| 16:9 | 1376×768 | 2752×1536 | 5504×3072 |
| 9:16 | 768×1376 | 1536×2752 | 3072×5504 |
| 4:3 | 1200×896 | 2400×1792 | 4800×3584 |
| 3:4 | 896×1200 | 1792×2400 | 3584×4800 |
| 21:9 | 1584×672 | 3168×1344 | 6336×2688 |
| 3:2 | 1248×832 | 2496×1664 | 4992×3328 |
| 2:3 | 832×1248 | 1664×2496 | 3328×4992 |
| 5:4 | 1152×896 | 2304×1792 | 4608×3584 |
| 4:5 | 896×1152 | 1792×2304 | 3584×4608 |
- 1K: Best for web display, social media, quick previews
- 2K: Best for high-quality printing, professional display
- 4K: Best for large prints, professional design, extreme detail
Complete Curl Example (Text-to-Image 4K)
Python Code Examples
💡 Progressive Examples Example 1 generates image → Example 2 transforms its style → Example 3 fuses both images. Clear progression! Example 1: Text-to-Image → Generate First ImageBash Script Example
Expand to view complete Bash script (with aspect ratio config)🚀 Gemini 3 Pro Advanced Features (Nano Banana Pro Exclusive)
🧠 Thinking Mode
Nano Banana Pro has built-in reasoning capability that automatically optimizes composition and logic before generating images to ensure higher quality output. This feature is enabled by default, no extra configuration needed. 💡 Thinking Mode Advantages- Automatically optimizes composition and layout
- Understands complex multi-step instructions
- Creates temporary “thinking images” during generation (backend only, no extra charge)
- Final output is higher quality and more aligned with expectations
🌐 Google Search Grounding
The model can use Google Search as a tool to generate images using real-time data (weather, stock prices, news).responseModalities must include "TEXT" (i.e., ["TEXT", "IMAGE"]). Pure image mode cannot return search results.
🎨 Multi-Image Reference (Reference Images)
Nano Banana Pro supports mixing up to 14 reference images:- Up to 6 high-fidelity object images (for inclusion in final image)
- Up to 5 person images (for maintaining character consistency)
- Object images: For product composition, scene building
- Person images: Maintain character appearance consistency (for image series)
- Combined use: Create complex visual narratives
💡 Best Practices
Prompt Optimization
Clear Description
Use specific, detailed descriptions including subject, style, color, lighting, etc.Reference Style
Specify art styles: “oil painting style”, “watercolor”, “cyberpunk style”, etc.Avoid Vagueness
Avoid overly abstract or vague termsEnglish First
English prompts typically work better, but Chinese is also supportedAspect Ratio Selection Guide
| Use Case | Recommended Ratio |
|---|---|
| Social media landscape | 16:9 |
| Phone wallpaper/vertical | 9:16 |
| Instagram square | 1:1 |
| Print photos | 4:3 or 3:2 |
| Movie posters | 2:3 |
| Banner ads | 21:9 |
❓ FAQ
How to test Nano Banana Pro API for free?- Visit api.yelinai.com to register
- Automatically receive $0.5 free credit
- Create token and select “Pay-per-use”
- Call the
gemini-3-pro-image-previewmodel
| Channel | Price | Notes |
|---|---|---|
| LaoZhang API | $0.09/image | 62.5% cheaper than official |
| Google Official | $0.24/image | Full price |
| Feature | Nano Banana Pro | Nano Banana |
|---|---|---|
| Model | gemini-3-pro-image-preview | gemini-2.5-flash-image |
| Technology | Gemini 3 | Gemini 2.5 |
| Resolution | 1K/2K/4K | 1K (fixed) |
| Price | $0.09/image | $0.025/image |
| Thinking Mode | ✅ Yes | ❌ No |
| Search Grounding | ✅ Yes | ❌ No |
| Multi-Image Reference | Up to 14 | Up to 3 |
- For 1:1 square images only, use OpenAI Compatible Mode - simpler
- For specific aspect ratios (like 16:9 widescreen) or high-res (2K/4K), use Google Native Format
imageSize parameter:
- Detailed description: Provide specific details (color, style, scene, etc.)
- English prompts: English typically works better
- Reference style: Specify art style (like “oil painting style”, “watercolor”)
- Multiple attempts: Try different prompts, pricing is affordable
🔗 Related Resources
Pro Image Editing
Learn how to edit and transform existing images with Nano Banana ProNano Banana2 Image Generation
$0.055/image, better value Banana2 versionStandard Image Generation
More affordable Nano Banana Standard versionToken Management
Create and manage your API tokensPricing
View detailed pricing and billing information📝 Changelog
2025-01: Nano Banana Pro standalone documentation launched 🚀 Nano Banana Pro Dedicated Page- Split from combined documentation into dedicated Pro version
- Complete 4K resolution usage guide
- Detailed advanced features (thinking mode, search grounding, multi-image reference)
- Complete code examples and best practices
- Comparison with Nano Banana Standard