Gemini 3.1 Pro Preview vs o3 Deep Research
Gemini 3.1 Pro Preview (2026) and o3 Deep Research (2025) are frontier reasoning models from Google DeepMind and OpenAI. Gemini 3.1 Pro Preview ships a 1m-token context window, while o3 Deep Research ships a 200k-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. It focuses on practical selection signals rather than broad model-family marketing.
Gemini 3.1 Pro Preview fits 5x more tokens; pick it for long-context work and o3 Deep Research for tighter calls.
Decision scorecard
Local evidence first| Signal | Gemini 3.1 Pro Preview | o3 Deep Research |
|---|---|---|
| Best for | multimodal apps, tool-calling agents, and long-context analysis | reasoning-heavy apps, multimodal apps, and tool-calling agents |
| Decision fit | Coding, RAG, and Agents | RAG, Agents, and Long context |
| Context window | 1m | 200k |
| Cheapest output | $12/1M tokens | $40/1M tokens |
| Provider routes | 5 tracked | 1 tracked |
| Shared benchmarks | 0 shared | 0 shared |
Decision tradeoffs
- Gemini 3.1 Pro Preview has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Gemini 3.1 Pro Preview has the lower cheapest tracked output price at $12/1M tokens.
- Gemini 3.1 Pro Preview has broader tracked provider coverage for fallback and procurement flexibility.
- Gemini 3.1 Pro Preview uniquely exposes Code execution in local model data.
- Local decision data tags Gemini 3.1 Pro Preview for Coding, RAG, and Agents.
- o3 Deep Research uniquely exposes Reasoning in local model data.
- Local decision data tags o3 Deep Research for RAG, Agents, and Long context.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Gemini 3.1 Pro Preview
$4,600
Cheapest tracked route/tier: Google AI Studio
o3 Deep Research
$18,000
Cheapest tracked route/tier: Vercel AI Gateway
Estimated monthly gap: $13,400. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on Vercel AI Gateway; start route-level A/B tests there.
- o3 Deep Research is $28/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Check replacement coverage for Code execution before moving production traffic.
- o3 Deep Research adds Reasoning in local capability data.
- Provider overlap exists on Vercel AI Gateway; start route-level A/B tests there.
- Gemini 3.1 Pro Preview is $28/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Reasoning before moving production traffic.
- Gemini 3.1 Pro Preview adds Code execution in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-02-19 | 2025-10-10 |
| Context window | 1m | 200k |
| Parameters | — | — |
| Architecture | Decoder Only | Decoder Only |
| License | Proprietary | Proprietary |
| Openness | Proprietary | Proprietary |
| Weights | Not released | Not released |
| Code | Unknown | Unknown |
| Commercial use | Commercial use: conditional | Commercial use: conditional |
| Knowledge cutoff | 2025-01 | 2024-06 |
Pricing and availability
| Pricing attribute | Gemini 3.1 Pro Preview | o3 Deep Research |
|---|---|---|
| Input price |
| $10/1M tokens |
| Output price |
| $40/1M tokens |
| Providers |
Capabilities
| Capability | Gemini 3.1 Pro Preview | o3 Deep Research |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | No | Yes |
| Function calling | Yes | Yes |
| Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | Yes | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark scores are currently available for this pair.
Deep dive
The capability footprint differs most on reasoning mode: o3 Deep Research and code execution: Gemini 3.1 Pro Preview. Both models share vision, multimodal input, function calling, and tool use, 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, Gemini 3.1 Pro Preview lists tiered pricing: 0-200,001t is $2/1M input and $12/1M output; 200,001t+ is $4/1M input and $18/1M output, while o3 Deep Research lists $10/1M input and $40/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Gemini 3.1 Pro Preview lower by about $14 per million blended tokens. For tiered rows, this cheapest-track view can understate interactive or fast-lane spend, so compare the tier you will actually use. Availability is 5 providers versus 1, so concentration risk also matters.
Choose Gemini 3.1 Pro Preview when coding workflow support, larger context windows, and lower cheapest-tier input-token cost are central to the workload. Choose o3 Deep Research when reasoning depth 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, Gemini 3.1 Pro Preview or o3 Deep Research?
Gemini 3.1 Pro Preview supports 1m tokens, while o3 Deep Research supports 200k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Which is cheaper, Gemini 3.1 Pro Preview or o3 Deep Research?
Gemini 3.1 Pro Preview lists tiered pricing: 0-200,001t is $2/1M input and $12/1M output; 200,001t+ is $4/1M input and $18/1M output. o3 Deep Research lists $10/1M input and $40/1M output tokens on the cheapest tracked provider. Compare the tier you will actually use; cheap async pricing can overstate savings for interactive workflows. Provider discounts or batch pricing can still change the final bill.
Is Gemini 3.1 Pro Preview or o3 Deep Research open source?
Gemini 3.1 Pro Preview is listed under Proprietary. o3 Deep Research 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, Gemini 3.1 Pro Preview or o3 Deep Research?
Both Gemini 3.1 Pro Preview and o3 Deep Research 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, Gemini 3.1 Pro Preview or o3 Deep Research?
Both Gemini 3.1 Pro Preview and o3 Deep Research 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 Gemini 3.1 Pro Preview and o3 Deep Research?
Gemini 3.1 Pro Preview is available on Google AI Studio, GCP Vertex AI, OpenRouter, Replicate API, and Vercel AI Gateway. o3 Deep Research is available on Vercel AI Gateway. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
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Last reviewed: 2026-06-29. Data sourced from public model cards and provider documentation.