Nano Banana 2.1 is an image generation and editing model from Google available through the SeedRouter API. It helps developers and designers create visuals with readable text and consistent characters across multiple edits. The model handles the common issue where AI-generated images contain garbled text or lose character consistency when you try to change a background or an outfit.
Software teams use this model to automate asset creation without worrying about the quality drops usually seen in wide-format or high-resolution renders. It works by processing text, image, video, or PDF inputs to generate a task ID, which then delivers a hosted URL once the image is ready. Because it uses a flat pricing model, you can experiment with different resolutions and reasoning depths without changing your budget.
Key Features
- Resolution options include 1K, 2K, and 4K at a single price point
- Text rendering is improved for menus, posters, and technical labels
- Reference handling supports up to 14 files, including 10 objects and 4 characters
- Aspect ratios range from 1:8 vertical strips to 8:1 panoramic banners
- Thinking levels allow you to choose between quick drafts and deep reasoning
- Google Search grounding connects the generation process to live web or image results
- Input formats include text, images, videos, and PDFs for context
- Tiling artifacts are removed for wide formats to ensure clean seams on panoramic renders
How to Use
- Log into your SeedRouter account and generate a unique API key
- Top up your balance with credits, which do not expire over time
- Send a POST request to the image generations endpoint with your prompt and any reference URLs
- Capture the task ID returned by the initial API response
- Poll the task status every few seconds until the status shows as completed
- Retrieve the hosted image URL from the final task output to save to your storage
Use Cases
- Creating a series of social media ads where the same character appears in different seasonal settings
- Generating website headers at 8:1 aspect ratio that include legible brand slogans
- Updating a product packshot by describing a new background while keeping the original bottle intact
- Building an infographic for a technical article that requires specific labels and layout logic
Pricing
Every image costs a flat $0.03, regardless of whether you choose 1K or 4K resolution. Failed requests are not charged, and there are no monthly subscription fees; you only pay for what you successfully generate.
FAQ
What is Nano Banana 2.1?
It is Google's updated model for text-to-image and editing tasks, officially known as Gemini 3.1 Flash Image. It focuses on better visual quality and steadier character consistency than previous versions.
Is Nano Banana 2.1 free?
No, it operates on a pay-per-image basis at $0.03 per successful generation. You need to top up your SeedRouter account before making API calls.
Can I generate multiple images at once?
Each request returns a single image task. To generate a batch, you should send multiple requests and track each task ID separately.
Do I need to host my own reference images?
You must provide references as public HTTP(S) links. The API does not accept base64 strings directly, though the playground interface handles uploads for you.
What happens if a generation fails?
SeedRouter does not charge your account balance for tasks that end in a failed status. You only pay for images that are successfully delivered to the CDN.
How does the thinking level affect the price?
The price remains $0.03 per image even if you set the thinking level to HIGH for more complex reasoning. Higher levels may take longer to process but do not cost more.
Can it read PDFs?
Yes, the model accepts PDFs as input to help guide the generation or editing process. This is useful for grounding images in specific documents or brand guidelines.
