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Nano Banana Pro: complex professional assets and 4K
  • Stable model ID: gemini-3-pro-image
  • LaoZhang API price: currently $0.09/call; confirm price and charges in the console
  • Professional capabilities: 1K/2K/4K, complex layout, text rendering, thinking, and Search grounding
  • Multi-image workflows: Brand assets, product images, posters, infographics, and precise editing

API Console

Create an API key, review balance, and inspect call logs

🚀 Live Demo

YingTu AI - Try instantly, no code required
LaoZhang API provides one global HTTPS endpoint, predictable per-call pricing, and call logs without a fixed low gateway concurrency plan. Final throughput still depends on Google upstream capacity, account state, and safety policy. For low-cost high-frequency 1K work, use Nano Banana 2 Lite; compare every route in the image generation API guide.

Prerequisites

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
Both modes have identical pricing at $0.09/image, only the billing method differs.
Pay-per-use billing note: Nano Banana Pro is billed based on successful calls returned by Google. If the prompt does not explicitly ask to generate or return image data, or if the text/reference image triggers Google’s official copyright, sensitive-person, or sensitive-content risk controls, the call may succeed without an image being returned. In that case, it is usually still charged as one successful call. Official 429/5xx errors, network timeouts, and parameter validation failures should be reviewed against console order status.
Token Settings
API calls will fail without proper billing configuration. Complete this setup first!

Model Overview

Nano Banana Pro is the market name for Google’s Gemini 3 Pro Image (gemini-3-pro-image). The current model ID is stable and designed for high-quality professional asset production and complex semantic control.

Core Advantages

  1. 🌟 Native 4K Resolution: Generate up to 4096×4096 ultra-high-definition images.
  2. 🧠 Gemini 3 Intelligence: Built-in logical reasoning, understands abstract descriptions like “a cat looking at an empty bowl with disappointment after missing breakfast”.
  3. 💪 Complex Composition: Precise control over object placement, quantity, and text rendering.
  4. 💰 Best Price: $0.09/image for premium image generation use cases.

🌟 Core Features

  • ⚡ Fast Response: ~10 seconds average, significantly faster than OpenAI series
  • 💰 Cost-Controlled: $0.09/image (current price shown in console)
  • 🔄 Dual Compatibility: Supports OpenAI SDK and Google native formats
  • 📐 Flexible Sizes: Google native format supports 14 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:
💡 How to Choose?
  • 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

💰 Pricing Details
  • Nano Banana Pro: LaoZhang API is currently $0.09/image; Google Standard is currently $0.134 at 1K/2K or $0.24 at 4K
  • Transparent billing: Review charges in call logs and confirm billing in the console

🚀 Quick Start

Prerequisites

1

Create Token

Login to LaoZhang API Token Management and create a pay-per-use type tokenToken Creation Interface
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

Supported Resolutions

💡 Resolution Selection Guide
  • 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!

Bash Script Example

🚀 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).
Note: When using search grounding, 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)
💡 Multi-Image Reference Best Practices
  • 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 terms

English First

English prompts typically work better, but Chinese is also supported

Aspect Ratio Selection Guide

❓ FAQ

  1. Visit api2.laozhang.ai to register
  2. Create token and select “Pay-per-use”
  3. Call the gemini-3-pro-image model
  4. Check actual charges in the console call logs
Actual charges are shown in the console call logs.
Check the console for the current price, balance, and any time-limited account activity before relying on it in a cost estimate.
Method 1: API Playground visual testingMethod 2: Curl command
  • 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
Both Nano Banana Pro and Nano Banana 2 support 4K. This page uses Pro through the Gemini-native format with an imageSize parameter:
Important: Must use uppercase “K” (1K, 2K, 4K).
Perfectly supported! Gemini 3 Pro has top-tier multilingual understanding. You can describe scenes in Chinese directly, no translation needed.
  1. Detailed description: Provide specific details (color, style, scene, etc.)
  2. English prompts: English typically works better
  3. Reference style: Specify art style (like “oil painting style”, “watercolor”)
  4. Multiple attempts: Try different prompts, pricing is affordable
Base64 data can be displayed directly in web pages:
Or decode and save as file (see code examples above)

Pro Image Editing

Learn how to edit and transform existing images with Nano Banana Pro

Nano Banana 2 Image Generation

$0.055/image, better value Banana 2 version

Standard Image Generation

More affordable Nano Banana Standard version

Token Management

Create and manage your API tokens

Pricing

View detailed pricing and billing information

📝 Changelog

🚀 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