Gemini 3.1 Flash Image — fast image generation and editing

Use gemini-3.1-flash-image-preview for fast creative iteration, reference-image edits, draft variants, and Gemini-native image workflows. It is available through both Quotaflow OpenAI-compatible image endpoints and Gemini-compatible generateContent.

What is Gemini 3.1 Flash Image?

Gemini 3.1 Flash Image is the fast image model in the Quotaflow creative catalog. It is a good first pass when you need many variants or quick feedback before choosing a final candidate.

Why use Gemini 3.1 Flash Image?

Use this model when speed and iteration count matter. Product teams can generate several concepts, review them quickly, and reserve slower or higher-cost image paths for final candidates.

Curated models

Key features

• Fast drafts: ideal for initial concepts and many variants.
• OpenAI-compatible option: call /openai/v1/images/generations or /images/edits from OpenAI-style clients.
• Gemini-native option: call :generateContent from Gemini-style clients.
• Reference-image edits: send source images and describe what should stay unchanged.
• OpenRouter-style image config: OpenAI-compatible JSON requests may include image_config.aspect_ratio and image_config.image_size; 0.5K is normalized to the Gemini-compatible 512 upstream value.

How to generate images

OpenAI-compatible generation:

curl https://api.quotaflow.ai/openai/v1/images/generations \
  -H "Authorization: Bearer $QUOTAFLOW_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gemini-3.1-flash-image-preview",
    "prompt": "A crisp social media image of a teal AI dashboard floating above a city map.",
    "size": "1024x1024",
    "image_config": { "aspect_ratio": "4:1", "image_size": "0.5K" },
    "response_format": "b64_json"
  }'

For gemini-3.1-flash-image-preview, image_config.aspect_ratio supports standard Gemini ratios plus wide/tall ratios such as 4:1, 1:4, 8:1, and 1:8. Use image_config.image_size values 0.5K, 1K, 2K, or 4K; Quotaflow sends 0.5K as 512 to Gemini-compatible upstreams.

Gemini-compatible generation:

curl "https://api.quotaflow.ai/v1beta/models/gemini-3.1-flash-image-preview:generateContent" \
  -H "x-goog-api-key: $QUOTAFLOW_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "contents": [
      {
        "role": "user",
        "parts": [
          { "text": "Create a clean 1:1 product marketing image for an AI API dashboard. Use teal accents and soft studio lighting." }
        ]
      }
    ],
    "generationConfig": {
      "responseModalities": ["IMAGE"],
      "imageConfig": { "aspectRatio": "1:1", "imageSize": "1K" }
    }
  }'

How to edit images

curl https://api.quotaflow.ai/openai/v1/images/edits \
  -H "Authorization: Bearer $QUOTAFLOW_API_KEY" \
  -F "model=gemini-3.1-flash-image-preview" \
  -F "image=@./source.png" \
  -F "prompt=Turn this into a premium product ad. Keep the main object recognizable and add clean teal lighting." \
  -F "size=1024x1024" \
  -F "response_format=b64_json"

Pricing

This model is a good starting point when you expect repeated creative iteration. Confirm key access and package limits before exposing high-volume generation to end users.

Use cases

FAQ

Should I choose Flash Image or Pro Image?

Start with Flash Image for speed and iteration. Use Pro Image when final quality or complex instruction following matters more than latency.

Can I use the OpenAI-compatible endpoint?

Yes. Use /openai/v1/images/generations and /openai/v1/images/edits if your app expects OpenAI-style image responses. For Gemini image JSON requests, you can also provide image_config with aspect_ratio and image_size when your client already uses OpenRouter-style image options.

Can I use Gemini generateContent?

Yes. Use the Gemini-compatible endpoint when your app already sends contents, parts, and generationConfig.

Next steps

• Compare with Gemini 3 Pro Image.
• Use GPT Image 2 for OpenAI-compatible image-first apps.
• Browse the Model Library.