- 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 laozhang.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
API calls will fail without proper billing configuration. Complete this setup first!
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
2
Select Billing Type
Important: Must select “Pay-per-use” type, not “Pay-as-you-go”
3
Save Token
Copy the generated token in format sk-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