Nano Banana 2 is Google's Gemini 3.1 Flash Image, a hosted image-generation and editing model positioned for speed and high-volume workflows. Use gemini-3.1-flash-image to identify it precisely, then measure request duration and accepted results with your own prompts. Model documentation
What are the key facts about Nano Banana 2?
| Fact | Verified detail |
|---|---|
| Developer | Google DeepMind. Announcement |
| Released | February 26, 2026, initial announcement; stable Gemini API version released May 28, 2026. Announcement, release notes |
| Type | Hosted image generation and editing; text, image, video, and PDF inputs, with image and text outputs. Model documentation |
| Size or parameters | Not published in the official model documentation. Model documentation |
| License and access | Google-hosted service with no open weights; API use follows Google's terms. Announcement, terms |
| Where it runs | Google's infrastructure, accessed through Gemini and developer services including AI Studio and Gemini API. Announcement |
“Nano Banana Flash” by itself is an ambiguous label. The original Nano Banana also has Flash in its technical name: Gemini 2.5 Flash Image.
Use the complete model identifier when asking which capabilities a workflow actually uses. Original documentation, Nano Banana 2 documentation
What does Nano Banana 2 offer for image workflows?
Google positions Nano Banana 2 as a speed-oriented image model and documents conversational editing.
Its model page also lists image-search grounding, additional output resolution options, and expanded aspect ratios. Model documentation
Include the controls your application needs in its evaluation brief.
Check whether the subject remains recognizable, whether the composition fits the intended shape, and whether the output can be used at the dimensions your project needs.
For an example task, create a square illustration of a bicycle repair stand, then request a wide composition with room for a headline. Compare subject placement and usable empty space rather than judging only the first impression.
The model's page lists thinking and search grounding as supported.
A task involving current information should therefore specify whether grounded generation is needed, then verify the resulting factual content against the underlying material. Model documentation
For an evergreen illustration, supply an explicit scene description and keep the task independent of current events. This makes the creative brief easier to evaluate and avoids introducing facts that were never necessary for the image.
What should you check when evaluating Nano Banana 2?
Flash is part of Google's model naming and positioning; the documentation does not establish a universal response time for your application.
Measure request duration with your actual prompts and selected settings before making a performance commitment. Model documentation
The same page does not publish a model parameter count or local weights.
Nano Banana 2 is a hosted service with no open weights, so its name should not be interpreted as a promise of phone, laptop, or edge-device inference. Model documentation, announcement
Google's image guide warns that the requested number of outputs may not be followed exactly. It also says image-search grounding does not currently support using real-world images of people from web search. Image generation guide
Treat format control and visual accuracy as separate checks. An image can have the requested shape while omitting a required object.
Review the full creative brief before accepting the result, including any text or relationships between subjects.
Old preview code needs attention as well. Google's release notes record the stable model's release and the June 25, 2026 shutdown date for its preview identifier.
Use the current model page when selecting an endpoint. Release notes
How do you test Nano Banana 2 in your own workflow?
Confirm which Flash image model you need
Write down the complete name before following a tutorial. Nano Banana 2 maps to gemini-3.1-flash-image; the original Nano Banana maps to gemini-2.5-flash-image.
Both are image models, but their documented capability tables differ. Current documentation, original documentation
If your reference tutorial uses a Pro model instead, consult the sibling Nano Banana Pro API migration guide.
That page explains the separate Gemini 3 Pro Image identifier.
Make a small API test
Create a Gemini API key in AI Studio and make it available as GEMINI_API_KEY. Google's key guide explains the project association and key-management steps. API key guide
Send a basic image-generation request before adding specialized controls.
The following example uses the stable Nano Banana 2 identifier and the documented generateContent request structure. Model documentation, API reference
curl --fail-with-body \
"https://generativelanguage.googleapis.com/v1beta/models/gemini-3.1-flash-image:generateContent" \
-H "x-goog-api-key: $GEMINI_API_KEY" \
-H "Content-Type: application/json" \
-d '{"contents":[{"parts":[{"text":"Create a clean illustration of a bicycle repair stand against a pale blue background."}]}],"generationConfig":{"responseModalities":["TEXT","IMAGE"]}}' \
-o response.json
The output file is a JSON envelope. Inspect the returned candidate parts, decode image data according to its MIME type, and handle errors or missing images before reporting success. API reference
Once the basic request works, choose the output shape and image size using the documented image configuration controls.
Google's guide describes these options; its model page identifies the resolution and aspect-ratio additions for Nano Banana 2. Image guide, model documentation
Evaluate the speed claim in your own workflow
Prepare a small set of tasks you actually expect to run. Include a simple scene, an edit with a reference, and an image containing approved text if those are relevant to your application. Use the same acceptance criteria throughout.
Record request duration and whether each output met the brief. Keep rejected attempts in your notes so the time needed to reach an accepted image remains visible. This is a suggested evaluation method, not a published benchmark.
Inspect quality alongside duration. A quick output that needs another attempt may have a different practical cost from a slower output accepted immediately. Let your actual task requirements determine how you weigh those outcomes.
How does Nano Banana 2 compare with the original Flash Image model?
| Model | Documented distinction |
|---|---|
| Original Nano Banana | Gemini 2.5 Flash Image; its capability table excludes thinking and search grounding. Documentation |
| Nano Banana 2 | Gemini 3.1 Flash Image; documents thinking, search grounding, and expanded image-format options. Documentation |
For arranging generation and editing steps visually, see the ComfyUI complete guide.
What are common Nano Banana 2 naming and speed questions?
What is the official name of Nano Banana 2?
Google identifies Nano Banana 2 as Gemini 3.1 Flash Image. The current model page lists gemini-3.1-flash-image as its stable identifier. Model documentation
Does every Nano Banana Flash reference mean Nano Banana 2?
No: the original Nano Banana is Gemini 2.5 Flash Image, so Flash alone does not distinguish the models.
Check the complete technical identifier in the workflow or provider documentation. Original documentation, current documentation
Can Nano Banana 2 run locally?
Nano Banana 2 is accessed as a hosted Google service, with no open model weights in the release. A local API client sends the generation request to that remote service. Announcement
Is a fixed generation time guaranteed?
Google positions Nano Banana 2 for speed, but its cited model documentation gives no universal per-image latency guarantee.
Measure your own workload instead of converting that positioning into a fixed number. Model documentation
Sources
- Google: Introducing Nano Banana 2
- Google: Gemini 3.1 Flash Image model documentation
- Google: Gemini 2.5 Flash Image model documentation
- Google: Gemini API release notes
- Google: Image generation guide
- Google: GenerateContent API reference
- Google: Using Gemini API keys
- Google: Gemini API service terms
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