Runflow
Google

Nano Banana 2 API

Nano Banana 2 by Google — fast image generation across 4 resolution tiers (0.5K–4K). Optional web search and thinking modes. SynthID watermarking on every output.

nano-banana-2 paramsGemini 3.1 Flash Image
Updated March 2026·Early access
Price
$0.08/image
At 1K resolution (standard)
Cold Start
5–10s
Not billed, handled by Runflow
Quality Score
Coming soon
Sentinel benchmarks in progress
Category
Image Generation
text-to-image

Nano Banana model family by Google

Two variants for different quality and cost needs — all on the same Runflow API.

Nano Banana 2

This model

Standard — fast generation from 0.5K to 4K resolution

Nano Banana Pro

Pro

Premium — higher quality, web search enabled, up to 4K

Benchmarked for your use case

Every model on Runflow is scored per vertical — not generic leaderboard numbers. Scores come from domain-expert evaluation on real production prompts.

Use CaseAssessmentNotes
PortraitStrongFast generation with natural skin tones and detail
FashionModerateGood quality across resolution tiers
ProductStrongClean rendering with SynthID watermarking
CreativeStrongFlexible with optional thinking mode for complex prompts

Pricing by resolution

Web search+$0.015· per image when enabled
High thinking+$0.002· per image when enabled
QualityPrice per imageMultiplier
0.5K (512px)$0.0600.75×
1K (standard)$0.080
2K$0.1201.5×
4K$0.160

$1.00 runs this model ~12 times at standard rate. Pricing is subject to change.

API Parameters

Full parameter reference for the nano-banana-2 model endpoint.

ParameterTypeDescription
promptstringText prompt describing the image. 3–50,000 characters.
resolutionstringOutput resolution. Options: "0.5K", "1K", "2K", "4K". Default: "1K". Price varies by tier.
aspect_ratiostringImage aspect ratio. Options: "21:9", "16:9", "3:2", "4:3", "5:4", "1:1", "4:5", "3:4", "2:3", "9:16", "4:1", "1:4", "8:1", "1:8". Use "auto" to let the model decide. Default: "auto".
enable_web_searchbooleanEnable web search to ground generation in current information. +$0.015/image. Default: false.
thinking_levelstringEnable model thinking. Options: "minimal", "high". Adds +$0.002/image at high level. Omit to disable.
num_imagesintegerNumber of images to generate. Range: 1–4. Default: 1.
output_formatstringOutput format. Options: "jpeg", "png", "webp". Default: "png".
safety_tolerancestringContent moderation level. 1 = most strict, 6 = least strict. Default: 4.
seedintegerRandom seed for reproducible outputs.
limit_generationsbooleanLimit to 1 image per prompt round regardless of prompt instructions. Default: true.
sync_modebooleanReturn media as data URI without storing in history. Default: false.

Technical Specifications

ArchitectureGemini 3.1 Flash Image
Resolutions0.5K · 1K · 2K · 4K
Aspect Ratios14 ratios including extreme (8:1, 1:8, 4:1, 1:4)
Add-onsWeb search · Model thinking
WatermarkingSynthID digital watermark
Output FormatsJPEG · PNG · WebP
LicenseCommercial

Why run Nano Banana 2 on the Runflow API

Flux AI models are available on many platforms. Here's what makes the Runflow image generation API different.

4 resolution tiers in one model

From 0.5K (fastest, cheapest) to 4K — choose the right resolution per request without switching models.

14 aspect ratios including extremes

Native support for 14 ratios from 21:9 to 1:8 — including panoramic (8:1) and ultra-tall (1:8) formats with no letterboxing.

Character consistency up to 5 people

Maintain consistent character appearance across up to 5 people in a single generation — ideal for storytelling, campaigns, and multi-character scenes.

SynthID watermarking

Every output carries Google's SynthID digital watermark, invisibly embedded and robust to common edits — enabling attribution and provenance tracking.

Web search + thinking modes

Optional web search grounds generation in current events. Thinking mode adds reasoning for complex prompts — both priced as add-ons.

Sentinel quality scoring

Every output is scored by Runflow's Sentinel system before delivery, catching low-quality results automatically.

Explore other models

Same API, different strengths. Switch models with one parameter change.

Frequently asked questions

Resources

Start generating images with Nano Banana 2

Get API access in minutes. No GPU setup, no infrastructure to manage. Pair with Sentinel to control the quality of every AI-generated image you ship.