Gemini Image Editing

Edit and transform existing images using text prompts with Google's Gemini 3 Pro model via fal.ai.

Prerequisites

• FAL_KEY environment variable must be set (typically in ~/.zshrc)

API Endpoint

POST https://fal.run/fal-ai/gemini-3-pro-image-preview/edit

Parameters

Required

• prompt (string): The editing instruction describing what changes to make
• image_urls (array of strings): URLs of the images to edit

Optional

| Parameter | Type | Default | Options | |-----------|------|---------|---------| | num_images | integer | 1 | 1-4 | | aspect_ratio | string | "auto" | "auto", "21:9", "16:9", "3:2", "4:3", "5:4", "1:1", "4:5", "3:4", "2:3", "9:16" | | output_format | string | "png" | "jpeg", "png", "webp" | | resolution | string | "1K" | "1K", "2K", "4K" | | sync_mode | boolean | false | Returns data URI when true | | enable_web_search | boolean | false | Uses current web data for generation | | limit_generations | boolean | false | Restricts to 1 image per prompt round |

Usage

cURL

curl --request POST \
  --url https://fal.run/fal-ai/gemini-3-pro-image-preview/edit \
  --header "Authorization: Key $FAL_KEY" \
  --header "Content-Type: application/json" \
  --data '{
    "prompt": "Add snow to this mountain scene and make it winter",
    "image_urls": ["https://example.com/mountain.jpg"],
    "num_images": 1,
    "output_format": "png"
  }'

Python

import fal_client

result = fal_client.subscribe(
    "fal-ai/gemini-3-pro-image-preview/edit",
    arguments={
        "prompt": "Add snow to this mountain scene and make it winter",
        "image_urls": ["https://example.com/mountain.jpg"],
        "num_images": 1
    }
)

# Access the edited image URL
edited_url = result["images"][0]["url"]
print(f"Edited image: {edited_url}")

JavaScript

import { fal } from "@fal-ai/client";

const result = await fal.subscribe("fal-ai/gemini-3-pro-image-preview/edit", {
  input: {
    prompt: "Add snow to this mountain scene and make it winter",
    image_urls: ["https://example.com/mountain.jpg"],
    num_images: 1
  }
});

console.log("Edited image:", result.images[0].url);

Response Format

{
  "images": [
    {
      "file_name": "edited_image.png",
      "content_type": "image/png",
      "url": "https://storage.googleapis.com/..."
    }
  ],
  "description": "A description of the edited image"
}

Examples

1. Style transformation:

   • Prompt: "Convert this photo to a watercolor painting style"

2. Object addition:

   • Prompt: "Add a rainbow in the sky"

3. Scene modification:

   • Prompt: "Change the time of day to sunset with golden hour lighting"

4. Multiple reference images:

   • Prompt: "Combine elements from these images into a cohesive scene"
   • Provide multiple URLs in image_urls array

Tips

• Be specific about what changes you want
• Use descriptive language for style changes
• Multiple images can be provided for context or combining elements
• The auto aspect ratio preserves the original image proportions

Error Handling

| Error | Cause | Solution | |-------|-------|----------| | 401 Unauthorized | Invalid FAL_KEY | Verify key at fal.ai dashboard | | 429 Too Many Requests | Rate limit exceeded | Wait 60 seconds, retry | | 400 Bad Request | Invalid image URL or parameters | Ensure image URLs are accessible | | 500 Server Error | API temporary issue | Retry after 30 seconds | | Timeout | Generation taking too long | Reduce resolution or simplify edit |