Image Generation Skill
Generate and edit website images using Gemini Native Image Generation.
⚠️ Critical: SDK Migration Required
IMPORTANT: The @google/generative-ai package is deprecated as of November 30, 2025. All new projects must use @google/genai.
Migration Required:
// ❌ OLD (deprecated, support ended Nov 30, 2025) import { GoogleGenerativeAI } from "@google/generative-ai"; const genAI = new GoogleGenerativeAI(API_KEY);
// ✅ NEW (required) import { GoogleGenAI } from "@google/genai"; const ai = new GoogleGenAI({ apiKey: API_KEY });
Source: GitHub Repository Migration Notice
Models Model ID Status Best For Gemini 3 Pro Image gemini-3-pro-image-preview Preview (Nov 20, 2025) 4K, complex prompts, text Gemini 2.5 Flash Image gemini-2.5-flash-image GA (Oct 2, 2025) Fast iteration, general use Imagen 4.0 imagen-4.0-generate-001 GA (Aug 14, 2025) Alternative platform
Deprecated Models (do not use):
gemini-2.0-flash-exp-image-generation - Shut down Nov 11, 2025 gemini-2.0-flash-preview-image-generation - Shut down Nov 11, 2025 gemini-2.5-flash-image-preview - Scheduled shutdown Jan 15, 2026
Source: Google AI Changelog
Capabilities Feature Supported Generate from text ✅ Edit existing images ✅ Change aspect ratio ✅ Widen/extend images ✅ Style transfer ✅ Change colours ✅ Add/remove elements ✅ Text in images ✅ (legible!) Multiple reference images ✅ (up to 14: max 5 humans, 9 objects) 4K resolution ✅ (Pro only)
Note: Exceeding 5 human reference images causes unpredictable character consistency. Keep human images ≤ 5 for reliable results.
Aspect Ratios 1:1 | 2:3 | 3:2 | 3:4 | 4:3 4:5 | 5:4 | 9:16 | 16:9 | 21:9
Resolutions (Pro only) Size 1:1 16:9 4:3 1K 1024x1024 1376x768 1184x880 2K 2048x2048 2752x1536 2368x1760 4K 4096x4096 5504x3072 4736x3520 Quick Start import { GoogleGenAI } from "@google/genai";
const ai = new GoogleGenAI({ apiKey: process.env.GEMINI_API_KEY });
// Generate new image const response = await ai.models.generateContent({ model: "gemini-2.5-flash-image", contents: "A professional plumber in hi-vis working in modern Australian home", config: { responseModalities: ["TEXT", "IMAGE"], // BOTH required - cannot use ["IMAGE"] alone imageGenerationConfig: { aspectRatio: "16:9", }, }, });
// Extract image for (const part of response.candidates[0].content.parts) { if (part.inlineData) { const buffer = Buffer.from(part.inlineData.data, "base64"); fs.writeFileSync("hero.png", buffer); } }
Important: responseModalities must include both ["TEXT", "IMAGE"]. Using ["IMAGE"] alone may fail or produce unexpected results.
Model Selection Requirement Use Fast iteration Gemini 2.5 Flash Image 4K resolution Gemini 3 Pro Image Preview Text in images Gemini 3 Pro (94% legibility at 4K) Simple edits Gemini 2.5 Flash Image Complex compositions Gemini 3 Pro Image Preview Infographics/diagrams Gemini 3 Pro Image Preview
Text Rendering Benchmarks (4K resolution):
Gemini 3 Pro Image: 94% legible text DALL-E 3: 78% legible text Midjourney: Decorative pseudo-text only When to Use
Use Gemini Image Gen when:
Stock photos don't fit brand/context Need Australian-specific imagery Need text in images (infographics, diagrams) Need consistent style across multiple images Need to edit/modify existing images Client has no photos of their work
Don't use when:
Client has good photos of actual work Real team photos needed (discuss first) Product shots (use real products) Legal/compliance concerns Known Issues Prevention
This skill prevents 5 documented issues:
Issue #1: Resolution Parameter Case Sensitivity
Error: Request fails with invalid parameter error Source: Google AI Image Generation Docs Why It Happens: Resolution values are case-sensitive and must use uppercase 'K'. Prevention: Always use "4K", "2K", "1K" - never lowercase "4k".
// ❌ WRONG - causes request failure config: { imageGenerationConfig: { resolution: "4k" } }
// ✅ CORRECT - uppercase required config: { imageGenerationConfig: { resolution: "4K" } }
Issue #2: Aspect Ratio May Be Ignored (Sept 2025+)
Error: Returns 1:1 square image despite requesting 16:9 or other ratios Source: Google Support Thread Why It Happens: Backend update in September 2025 affected Gemini 2.5 Flash Image model's aspect ratio handling. Prevention: Use Gemini 3 Pro Image Preview for reliable aspect ratio control, or generate 1:1 and use multi-turn editing to extend.
// May ignore aspectRatio on Gemini 2.5 Flash Image model: "gemini-2.5-flash-image", config: { imageGenerationConfig: { aspectRatio: "16:9" } }
// More reliable for aspect ratio control model: "gemini-3-pro-image-preview", config: { imageGenerationConfig: { aspectRatio: "16:9" } }
Status: Google confirmed working on fix (Sept 2025).
Issue #3: Exceeding 5 Human Reference Images
Error: Unpredictable character consistency in generated images Source: Google AI Image Generation Docs Why It Happens: Gemini 3 Pro Image supports up to 14 reference images total, but only 5 can be human images for character consistency. Prevention: Limit human images to 5 or fewer. Use remaining slots (up to 14 total) for objects/scenes.
// ❌ WRONG - 7 human images exceeds limit const humanImages = [img1, img2, img3, img4, img5, img6, img7]; const prompt = [ { text: "Generate consistent characters" }, ...humanImages.map(img => ({ inlineData: { data: img, mimeType: "image/png" }})), ];
// ✅ CORRECT - max 5 human images const humanImages = images.slice(0, 5); // Limit to 5 const objectImages = images.slice(5, 14); // Up to 9 more for objects const prompt = [ { text: "Generate consistent characters" }, ...humanImages.map(img => ({ inlineData: { data: img, mimeType: "image/png" }})), ...objectImages.map(img => ({ inlineData: { data: img, mimeType: "image/png" }})), ];
Issue #4: SynthID Watermark Cannot Be Disabled
Error: N/A (documented limitation) Source: Google AI Image Generation Docs Why It Happens: All generated images automatically include a SynthID watermark for content authenticity tracking. Prevention: Be aware of this limitation for commercial use cases. Watermark cannot be disabled by developers.
Issue #5: Google Search Grounding Excludes Image Results
Error: Generated images don't reflect visual search results, only text Source: Google AI Image Generation Docs Why It Happens: When using Google Search tool with image generation, "image-based search results are not passed to the generation model." Prevention: Only text-based search results inform the visual output. Don't expect the model to reference images from search results.
// Google Search tool enabled const response = await ai.models.generateContent({ model: "gemini-3-pro-image-preview", contents: "Generate image of latest iPhone design", tools: [{ googleSearch: {} }], config: { responseModalities: ["TEXT", "IMAGE"] }, }); // Result: Only text search results used, not image results from web search
Pricing
Current Pricing (as of November 2025):
Gemini 2.5 Flash Image: ~$0.008 per image Input: 258 tokens per image Output: 1290 tokens per image Rate: $30.00 per 1M output tokens
Note: The generateImages API (Imagen models) does not return usageMetadata in responses. Track costs manually based on pricing above.
Source: Google Developers Blog - Gemini 2.5 Flash Image
Reference Files references/prompting.md - Effective prompt patterns references/website-images.md - Hero, service, background templates references/editing.md - Multi-turn editing patterns references/local-imagery.md - Australian-specific details references/integration.md - API code examples
Last verified: 2026-01-21 | Skill version: 2.0.0 | Changes: Added SDK migration notice (critical), updated to current model names (gemini-3-pro-image-preview, gemini-2.5-flash-image), added 5 Known Issues (resolution case sensitivity, aspect ratio bug, reference image limits, SynthID watermark, Google Search grounding), added pricing section, added text rendering benchmarks.