gemini-3.1-flash-image-preview
Provider list prices: no platform markup, pay-as-you-go. These are official list prices. Logged-in customers may see effective prices including workspace discounts on /console/pricing.
Use gemini-3.1-flash-image-preview in 30 seconds
OpenAI-compatible: swap the base_url, keep your SDK. POST /v1/images/generations
from openai import OpenAI
client = OpenAI(
base_url="https://synthorai.io/v1",
api_key="sk-syn-...",
)
resp = client.images.generate(
model="gemini-3.1-flash-image-preview",
prompt="a watercolor lighthouse at dawn",
size="1024x1024",
)
print(resp.data[0].b64_json[:80])import OpenAI from "openai";
const client = new OpenAI({
baseURL: "https://synthorai.io/v1",
apiKey: "sk-syn-...",
});
const resp = await client.images.generate({
model: "gemini-3.1-flash-image-preview",
prompt: "a watercolor lighthouse at dawn",
size: "1024x1024",
});
console.log(resp.data?.[0]?.b64_json?.slice(0, 80));curl https://synthorai.io/v1/images/generations \
-H "Authorization: Bearer sk-syn-..." \
-H "Content-Type: application/json" \
-d '{
"model": "gemini-3.1-flash-image-preview",
"prompt": "a watercolor lighthouse at dawn",
"size": "1024x1024"
}'package main
import (
"context"
"fmt"
"github.com/openai/openai-go/v3"
"github.com/openai/openai-go/v3/option"
)
func main() {
client := openai.NewClient(
option.WithBaseURL("https://synthorai.io/v1"),
option.WithAPIKey("sk-syn-..."),
)
resp, _ := client.Images.Generate(context.TODO(), openai.ImageGenerateParams{
Model: "gemini-3.1-flash-image-preview",
Prompt: "a watercolor lighthouse at dawn",
Size: "1024x1024",
})
fmt.Println(resp.Data[0].B64JSON[:80])
}import com.openai.client.OpenAIClient;
import com.openai.client.okhttp.OpenAIOkHttpClient;
import com.openai.models.images.*;
OpenAIClient client = OpenAIOkHttpClient.builder()
.baseUrl("https://synthorai.io/v1")
.apiKey("sk-syn-...")
.build();
ImagesResponse resp = client.images().generate(
ImageGenerateParams.builder()
.model("gemini-3.1-flash-image-preview")
.prompt("a watercolor lighthouse at dawn")
.size("1024x1024")
.build());
System.out.println(resp.data().orElseThrow().get(0).b64Json().orElseThrow().substring(0, 80));About gemini-3.1-flash-image-preview
Gemini 3.1 Flash Image (preview), marketed as Nano Banana 2, delivers high-quality image generation and conversational editing at low latency as the efficient counterpart to Nano Banana Pro.
- Versus the earlier Nano Banana generation, the official page highlights expanded resolution support (0.5K, 1K, 2K, and 4K), new extreme aspect ratios such as 1:4 and 8:1, Image Search Grounding that blends web text and image results, and improved aspect-ratio adherence, image consistency, and international text rendering.
- Input tokens reach 131,072 with 32,768 output.
- Synthorai serves the model over its OpenAI-compatible API surface.
Specs & limits
| Max output (vendor spec) | 32,768 |
| Modalities | text + image → image + text |
| Features | vision · batch · reasoning |
| Image capabilities | 0.5K/2K/4K output (default 1K); conversational image editing; extended aspect ratios incl. 1:4, 4:1, 1:8, 8:1; improved i18n text rendering; search grounding supported |
| Notable | Gateway preview id has no live official page; GA model code is gemini-3.1-flash-image (released 2026-05-28); caching, function calling, structured outputs not supported. |
FAQ
Is the gemini-3.1-flash-image-preview API free to try?
Yes: new accounts get 10 trial calls and up to $1 in free credit, no card required. That's enough to try gemini-3.1-flash-image-preview against your real workload before adding a payment method.
What is gemini-3.1-flash-image-preview best at?
Expanded resolution from 0.5K to 4K, plus extreme aspect ratios like 1:4 and 8:1 and image search grounding blends web results. See the About section for the full picture from the vendor's own release notes.
How much does gemini-3.1-flash-image-preview cost?
gemini-3.1-flash-image-preview costs $0.5 per million input tokens and $60 per million output tokens on Synthorai. That is the provider's list price, with no platform markup.
How do I generate images with the gemini-3.1-flash-image-preview API?
POST to /v1/images/generations on Synthorai with model="gemini-3.1-flash-image-preview". It follows the OpenAI images API shape, so no vendor SDK is needed.
How do I get access to gemini-3.1-flash-image-preview?
Point your existing OpenAI SDK at base_url="https://synthorai.io/v1", set model="gemini-3.1-flash-image-preview", and you're done. One API key covers every model on the gateway.