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Documentation Index

Fetch the complete documentation index at: https://docs.apiyi.com/llms.txt

Use this file to discover all available pages before exploring further.

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Overview

Nano Banana 2 (codename) is Google’s latest image generation model released on February 26, 2026, with model ID gemini-3.1-flash-image-preview. It redefines image generation cost-effectiveness with Pro-level quality at Flash-tier speed and cost, making it the latest flagship of the Nano Banana series.
🔥 Released February 26, 2026: Nano Banana 2 is live! Pro-level quality, Flash-tier speed, token-based billing as low as 28% of Google’s pricing! 512px from just $0.025/image! Supports 4K output, 14 aspect ratios, Image Search Grounding, and more exclusive features.

Text-to-Image API

Generate images from text prompts. Includes an interactive playground for online testing.

Image Editing API

Upload an image + edit instructions to generate new images. Includes an interactive playground.

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Why APIYI’s Nano Banana 2?

Nano Banana Pro / 2 is the #1 model by usage volume on APIYI — stable, reliable, and fast. If you want to work with a professional team, APIYI is the right choice. A freshly released Google flagship still capacity-constrained at the source — APIYI deeply optimizes the experience across reliability, cost, and integration:

Official Channel · Same as Gemini

100% compatible with Google’s native Gemini API (/v1beta/models/.../generateContent) and the OpenAI SDK pattern — same request body, response fields, and error codes. Zero-code migration.

No Concurrency Limits

Not bound by Google AI Studio’s RPM/RPD ceilings. Enterprise-scale batch generation and peak traffic scale linearly without quota interruptions.

28-36% of Google's List Price

$0.055/image per-call (vs Google $0.151), 512px from $0.025/image token-based (vs $0.045). Stack with top-up bonuses for as low as 30.3% of the list.

Global Zero-Barrier Access

No overseas server or proxy required — connect directly to api.apiyi.com from mainland data centers, residential networks, or overseas nodes. Stable latency, no cross-border re-architecture.

Full Model Lineup

Same series covers Nano Banana Pro (ultimate quality), Nano Banana 2 (best value), and the legacy Nano Banana — mix and match per scenario.

Professional Enterprise Support

Our team specializes in production image-generation deployments, with deep experience in model selection, tuning, and integration — end-to-end support from PoC to production.

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Core Features

Pro-Level Quality

Vibrant lighting, rich textures, sharp details - quality rivaling Nano Banana Pro at much faster speeds

4K Ultra-HD Output

Supports 512px, 1K, 2K, 4K resolutions, up to 4096×4096

14 Aspect Ratios

New additions: 1:4, 4:1, 1:8, 8:1 - total 14 aspect ratios covering more use cases

Image Search Grounding

Nano Banana 2 exclusive - pulls visual context from Google Image Search

Accurate Text Rendering

Clear, legible text in images with multilingual support - perfect for posters and marketing materials

Multi-turn Editing

Conversational image editing with iterative refinement through chat

Thinking Mode

Configurable minimal or high thinking levels for more precise complex prompt handling

Subject Consistency

Maintains resemblance across up to 5 characters and 14 reference objects

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Version Comparison

FeatureNano Banana 2Nano Banana ProNano Banana
Model IDgemini-3.1-flash-image-previewgemini-3-pro-image-previewgemini-2.5-flash-image
Quality⭐⭐⭐⭐⭐ Pro-level⭐⭐⭐⭐⭐ Highest⭐⭐⭐⭐ Excellent
Speed🚀 Fastest🐢 Slower⚡ Fast
Max Resolution4K4K1K
Aspect Ratios141010
Image Search Grounding✅ Exclusive❌❌
APIYI Pricing$0.055/image (per-call)$0.09/image$0.02/image
StatusPreviewPreviewGA
Selection Guide:
  • 🔥 Best Value → Nano Banana 2 (token-based from $0.025/image, Pro-level quality + Flash-tier speed)
  • 🎨 Ultimate Quality → Nano Banana Pro ($0.09/image, highest fidelity)
  • ⚡ Lowest Cost → Nano Banana ($0.025/image, fast and stable)

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Pricing

Billing Mode Selection: Nano Banana 2 supports two billing modes, selected via the “Billing model” setting when creating your API token:
  • Select Pay-as-you-go or Pay-as-you-go Priority → Token-based billing
  • Select Pay-per-request or Pay-per-request Priority → Per-call billing (same as Nano Banana Pro)
  • ⚠️ Do NOT select Hybrid billing

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Per-call Billing

ModelAPIYI PricingGoogle Official 4KDiscount
Nano Banana 2 gemini-3.1-flash-image-preview$0.055/image$0.151/image🔥 ~64% off
Nano Banana Pro gemini-3-pro-image-preview$0.09/image$0.24/image~63% off
Nano Banana gemini-2.5-flash-image$0.02/image$0.039/image (1K only)~50% off
Enterprise HA Channel: NanoBananaEnterprise is available at 1.4x the standard Nano Banana Pro rate ($0.126/image), offering a dedicated high-availability fallback for enterprise workloads.

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Token-based Billing (Nano Banana 2 Exclusive)

Billing ItemGoogle OfficialAPIYIDiscount
Input$0.50/M tokens$0.14/M tokens28%
Output (images and text unified)Images $60/M, Text $1.5/M$16.8/M tokens28%

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Token-based Billing Price Estimates

ResolutionGoogle OfficialAPIYIFal AI
512px$0.045~$0.025$0.06
1K$0.067~$0.035$0.08
2K$0.101~$0.045$0.12
4K$0.151~$0.07$0.16
💰 Token-based billing saves more! With token-based billing, 512px images from just $0.025 — only 28% of Google’s pricing! For low-resolution use cases, this is much cheaper than per-call billing ($0.055/image). For 4K, token-based pricing (~$0.07) is even cheaper than per-call billing, and both are far below Google’s official $0.151/image. Combined with top-up bonuses, actual costs are even lower.

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Group Setup

Nano Banana 2 ships with two groups on APIYI. Switch in dashboard → Token Settings:
GroupRateWhen to use
Default1.0xBase lane, matches the price table; recommended default
NanoBananaEnterprise1.4xFallback lane — manually switch when the default is tight or timeouts spike, capacity-prioritized
Why 1.4x? Even at 1.4x, the price is still around 50% of Google’s list — far below official pricing. This is a fallback lane for higher-concurrency workloads and unexpected upstream risk-control events, providing high-availability guarantees for enterprise customers. When the default group is tight, switch your Token to NanoBananaEnterprise to ride out the spike. Recommended Billing model: pick Pay-as-you-go Priority — covers Nano Banana 2’s token-based billing AND Nano Banana Pro’s per-call billing, one Token for the whole series.
Token creation UI: Billing model 'Pay-as-you-go Priority' covers NB2 token-based + NB Pro per-call; primary group Default + fallback group NanoBananaEnterprise (1.4x lane)
Going further: if your Token also covers other image models (e.g. GPT-image-2), keep the more stable Default as the primary group and put NanoBananaEnterprise in the fallback slot — 429s on the primary will auto-failover to the enterprise group without a token swap.

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Supported Resolutions & Aspect Ratios

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Output Resolutions

ResolutionDescriptionRecommended Use
512pxLow resolutionThumbnails, quick previews
1KDefaultSocial media, web display
2KHigh definitionHD displays, print materials
4KUltra-high definitionProfessional design, commercial posters

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Supported Aspect Ratios (14 total)

1:1, 1:4, 4:1, 1:8, 8:1, 2:3, 3:2, 3:4, 4:3, 4:5, 5:4, 9:16, 16:9, 21:9
Compared to Nano Banana Pro’s 10 aspect ratios, Nano Banana 2 adds 1:4, 4:1, 1:8, 8:1 - ultra-tall/ultra-wide ratios ideal for long-form images and infographics.

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FAQ

Nano Banana 2 (gemini-3.1-flash-image-preview) is based on Gemini 3.1 Flash, while Nano Banana Pro (gemini-3-pro-image-preview) is based on Gemini 3 Pro. Key differences:
  • ✅ Speed: Nano Banana 2 is faster (Flash-tier speed)
  • ✅ Price: Nano Banana 2 token-based billing is cheaper (from $0.025 vs $0.09)
  • ✅ Aspect Ratios: Nano Banana 2 supports 14 (4 more)
  • ✅ Image Search Grounding: Nano Banana 2 exclusive
  • ⚠️ Ultimate Quality: Nano Banana Pro still slightly better
Recommended! Nano Banana 2 offers near-Pro-level quality at a lower price with faster speed. Unless you have extreme quality requirements, Nano Banana 2 is the better choice.Simply change the model name from gemini-3-pro-image-preview to gemini-3.1-flash-image-preview.
For code / API calls, we recommend always using the general model name gemini-3.1-flash-image-preview (without the -4k suffix), not gemini-3.1-flash-image-preview-4k.
  • The official name has no -4k: Google’s official model name is gemini-3.1-flash-image-preview. This is also the general channel we invest the most resources in maintaining, so it offers the best stability and compatibility.
  • Where -4k comes from: gemini-3.1-flash-image-preview-4k was originally a configuration prepared for “chat-to-image” scenarios in conversational clients like Chatbox—generating images directly through chat in a messaging UI.
  • Code + Gemini native format favors the general name: If you’re calling via code using the Gemini native format (/v1beta/models/.../generateContent), the regular model name gemini-3.1-flash-image-preview is more stable.
When you need 4K output, there’s no need to rely on the -4k model name—just specify the 4K resolution in your request parameters (see “Supported Resolutions and Aspect Ratios” above).
Image Search Grounding is a Nano Banana 2 exclusive feature. It pulls visual context from Google Image Search to generate images that better match real-world subjects. For example, when generating images of real landmarks, it can reference search results for improved accuracy.
Thinking Mode allows the model to reason and analyze before generating images, improving accuracy for complex prompts. Setting it to high produces the best results but slightly increases generation time. Best for tasks requiring precise composition, text rendering, or complex scenes.
Generation time depends on resolution and thinking mode:
  • 1K resolution: ~5-10 seconds
  • 2K resolution: ~10-15 seconds
  • 4K resolution: ~15-25 seconds
  • Enabling high thinking mode adds a few extra seconds
Recommend setting a longer timeout (at least 360 seconds) for occasional delays and peak congestion.
The API has no concurrency limit and does not process serially. You can safely fire concurrent requests yourself — requests don’t queue or block each other. For 20 users calling simultaneously, just issue 20 concurrent requests; no extra quota request or throttling needed.Unlike Google AI Studio, the API易 channel has no hard RPM/RPD limits, so enterprise batch generation and peak traffic scale linearly.What actually matters is the timeout: image generation (especially 4K or during peak congestion) can take a while per request, so set your client timeout to 360 seconds to avoid cutting off requests that are still being processed normally.
If you occasionally hit 429 (throttled due to high concurrency), add NanoBananaEnterprise as the fallback group on your token (see “Group Setup” above). When the primary group is saturated it auto-falls back, further improving success rates under high concurrency.
Supports image/png and image/jpeg formats. Can be uploaded via base64 encoding or Files API.
All output images carry SynthID invisible digital watermarks (Google’s AI-generated content identification technology) - invisible to the naked eye and doesn’t affect usage.
Nano Banana 2 is currently in Preview status. Features and pricing may be adjusted. Please follow documentation updates for the latest information.