Nano Banana 2 (Gemini 3.1 Flash Image) vs GPT-5.5 Instant
Nano Banana 2 (Gemini 3.1 Flash Image) (2026) and GPT-5.5 Instant (2026) are frontier reasoning models from Google DeepMind and OpenAI. Nano Banana 2 (Gemini 3.1 Flash Image) ships a 131k-token context window, while GPT-5.5 Instant ships a 400k-token context window. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
Nano Banana 2 (Gemini 3.1 Flash Image) is ~900% cheaper at $0.50/1M; pay for GPT-5.5 Instant only for coding workflow support.
Decision scorecard
Local evidence first| Signal | Nano Banana 2 (Gemini 3.1 Flash Image) | GPT-5.5 Instant |
|---|---|---|
| Best for | reasoning-heavy apps and multimodal apps | multimodal apps and tool-calling agents |
| Decision fit | Long context and Vision | Coding, RAG, and Agents |
| Context window | 131k | 400k |
| Cheapest output | $60/1M tokens | $30/1M tokens |
| Provider routes | 1 tracked | 1 tracked |
| Shared benchmarks | 0 rows | 0 rows |
Decision tradeoffs
- Nano Banana 2 (Gemini 3.1 Flash Image) uniquely exposes Reasoning in local model data.
- Local decision data tags Nano Banana 2 (Gemini 3.1 Flash Image) for Long context and Vision.
- GPT-5.5 Instant has the larger context window for long prompts, retrieval packs, or transcript analysis.
- GPT-5.5 Instant has the lower cheapest tracked output price at $30/1M tokens.
- GPT-5.5 Instant uniquely exposes Function calling, Tool use, and Structured outputs in local model data.
- Local decision data tags GPT-5.5 Instant for Coding, RAG, and Agents.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Nano Banana 2 (Gemini 3.1 Flash Image)
$15,400
Cheapest tracked route/tier: Google AI Studio
GPT-5.5 Instant
$11,500
Cheapest tracked route/tier: OpenAI API
Estimated monthly gap: $3,900. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- No overlapping tracked provider route is sourced for Nano Banana 2 (Gemini 3.1 Flash Image) and GPT-5.5 Instant; plan for SDK, billing, or endpoint changes.
- GPT-5.5 Instant is $30/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Reasoning before moving production traffic.
- GPT-5.5 Instant adds Function calling, Tool use, and Structured outputs in local capability data.
- No overlapping tracked provider route is sourced for GPT-5.5 Instant and Nano Banana 2 (Gemini 3.1 Flash Image); plan for SDK, billing, or endpoint changes.
- Nano Banana 2 (Gemini 3.1 Flash Image) is $30/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Check replacement coverage for Function calling, Tool use, and Structured outputs before moving production traffic.
- Nano Banana 2 (Gemini 3.1 Flash Image) adds Reasoning in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-05-28 | 2026-05-05 |
| Context window | 131k | 400k |
| Parameters | — | — |
| Architecture | decoder only | decoder only |
| License | Proprietary | Proprietary |
| Knowledge cutoff | 2025-01 | 2025-08 |
Pricing and availability
| Pricing attribute | Nano Banana 2 (Gemini 3.1 Flash Image) | GPT-5.5 Instant |
|---|---|---|
| Input price | $0.50/1M tokens | $5/1M tokens |
| Output price | $60/1M tokens | $30/1M tokens |
| Providers |
Capabilities
| Capability | Nano Banana 2 (Gemini 3.1 Flash Image) | GPT-5.5 Instant |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | No |
| Function calling | No | Yes |
| Tool use | No | Yes |
| Structured outputs | No | Yes |
| Code execution | No | Yes |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint differs most on reasoning mode: Nano Banana 2 (Gemini 3.1 Flash Image), function calling: GPT-5.5 Instant, tool use: GPT-5.5 Instant, structured outputs: GPT-5.5 Instant, and code execution: GPT-5.5 Instant. Both models share vision and multimodal input, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.
For cost, Nano Banana 2 (Gemini 3.1 Flash Image) lists $0.50/1M input and $60/1M output tokens on the cheapest tracked provider, while GPT-5.5 Instant lists $5/1M input and $30/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts GPT-5.5 Instant lower by about $5.85 per million blended tokens. Availability is 1 providers versus 1, so concentration risk also matters.
Choose Nano Banana 2 (Gemini 3.1 Flash Image) when reasoning depth and lower input-token cost are central to the workload. Choose GPT-5.5 Instant when coding workflow support and larger context windows are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.
FAQ
Which has a larger context window, Nano Banana 2 (Gemini 3.1 Flash Image) or GPT-5.5 Instant?
GPT-5.5 Instant supports 400k tokens, while Nano Banana 2 (Gemini 3.1 Flash Image) supports 131k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Which is cheaper, Nano Banana 2 (Gemini 3.1 Flash Image) or GPT-5.5 Instant?
GPT-5.5 Instant is cheaper on tracked token pricing. Nano Banana 2 (Gemini 3.1 Flash Image) costs $0.50/1M input and $60/1M output tokens. GPT-5.5 Instant costs $5/1M input and $30/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Nano Banana 2 (Gemini 3.1 Flash Image) or GPT-5.5 Instant open source?
Nano Banana 2 (Gemini 3.1 Flash Image) is listed under Proprietary. GPT-5.5 Instant is listed under Proprietary. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
Which is better for vision, Nano Banana 2 (Gemini 3.1 Flash Image) or GPT-5.5 Instant?
Both Nano Banana 2 (Gemini 3.1 Flash Image) and GPT-5.5 Instant expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Which is better for multimodal input, Nano Banana 2 (Gemini 3.1 Flash Image) or GPT-5.5 Instant?
Both Nano Banana 2 (Gemini 3.1 Flash Image) and GPT-5.5 Instant expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Where can I run Nano Banana 2 (Gemini 3.1 Flash Image) and GPT-5.5 Instant?
Nano Banana 2 (Gemini 3.1 Flash Image) is available on Google AI Studio. GPT-5.5 Instant is available on OpenAI API. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
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Last reviewed: 2026-05-31. Data sourced from public model cards and provider documentation.