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Gemini

Nano Banana 2

ID:google/nano-banana-2

Nano Banana 2 image generation API by Google — Gemini 3.1 Flash with 4K output, 15 aspect ratios, and character consistency for up to 5 characters.

Text to imageImage editingReference images4KText rendering
Input
Aspect ratio
Resolution
Reference images
Max 14 images, 30MB each
OutputView all
Output will appear here
1K
$0.06
2K
$0.09
4K
$0.13
cURL
curl https://api.runbase.net/v1/runs \
  -H "Authorization: Bearer $RUNBASE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "google/nano-banana-2",
    "input": {
      "prompt": "A cinematic product photo of a ceramic lamp",
      "aspect_ratio": "1:1",
      "resolution": "1K"
    }
  }'

Examples

DIY infographic

DIY infographic

16:9

High-quality flat lay photography creating a DIY infographic that simply explains how the water cycle works, with hand-drawn arrows and labels.

Labeled triptych

Labeled triptych

16:9

A three-panel comic-style comparison of Cumulus, Stratus, and Cirrus clouds in dramatic skies, each panel with a bold legible label.

Character consistency

Character consistency

16:9

A four-panel collage of the same kangaroo character in a consistent outfit across vacation scenes — boating, a café, a hotel room, and a bouncy castle.

Overview

Nano Banana 2 is the most versatile model in Google's Nano Banana family, released in February 2026. Built on Gemini 3.1 Flash, it delivers Pro-level quality at Flash speed. It supports 15 aspect ratios — the widest selection available — including ultra-wide options (8:1, 1:8) and auto. Output resolution goes up to 4K. It accepts up to 14 reference images at 30 MB each and can maintain character consistency for up to 5 distinct characters across images.

Use cases

High-volume brand asset production at scale. Character-consistent workflows — comics, storyboards, mascot campaigns. Infographics and diagrams with accurate text rendering. Ultra-wide banners and panoramic compositions using 8:1 or 21:9 ratios. Reference-guided editing with up to 14 images.

Inputs

All parameters are passed in the input object of the run request.

ParameterRequiredDescription
promptYesText description (1–20000 chars)
aspect_ratioNoOutput aspect ratio. Default 1:1. Supports 15 ratios including ultra-wide (8:1, 1:8) and auto
resolutionNoOutput resolution. Default 1K. Options: 1K, 2K, 4K
image_urlsNoUp to 14 reference images (max 30 MB each) for guided generation

Prompt tips

Describe characters with consistent identifiers

When using character consistency, give each character a distinct visual description and refer to them consistently across prompts. "The red-haired fox in a blue scarf" should stay the same phrase each time.

Match resolution to use case

1K is fast and cheap for iteration. 2K balances quality and cost. Reserve 4K for final deliverables — the price difference is significant.

Use ultra-wide ratios deliberately

8:1 and 1:8 are powerful for banners and vertical scrolls, but they require prompts that fill the space. Describe a scene with enough elements to avoid sparse compositions.

Limitations

  • Ultra-wide ratios (8:1, 1:8) may produce stretched or sparse compositions
  • Flash-speed trade-off: slightly less reasoning depth than Pro on complex prompts
  • Character consistency limited to 5 distinct characters
  • Maximum 14 reference images per request, 30 MB each
  • Prompt length capped at 20,000 characters

FAQ

What aspect ratios does Nano Banana 2 support?

Fifteen options: 1:1, 1:4, 1:8, 2:3, 3:2, 3:4, 4:1, 4:3, 4:5, 5:4, 8:1, 9:16, 16:9, 21:9, and auto. The default is 1:1.

What resolutions are available?

1K (default), 2K, and 4K. Each resolution tier has a different price point.

How does character consistency work?

Describe up to 5 characters with distinct visual traits and the model will maintain their appearance across generated images. Use reference images to further anchor each character's look.