Gemini 2.5 Pro vs o3 Mini
Gemini 2.5 Pro (2025) and o3 Mini (2025) are frontier reasoning models from Google DeepMind and OpenAI. Gemini 2.5 Pro ships a 1M-token context window, while o3 Mini ships a not-yet-sourced context window. On MMLU PRO, Gemini 2.5 Pro leads by 7.1 pts. On pricing, o3 Mini costs $1.1/1M input tokens versus $1.25/1M for the alternative. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit.
Pick Gemini 2.5 Pro for general evaluation; o3 Mini is better when coding workflow support matters more.
Specs
| Released | 2025-06-17 | 2025-03-31 |
| Context window | 1M | — |
| Parameters | — | — |
| Architecture | decoder only | decoder only |
| License | Proprietary | Unknown |
| Knowledge cutoff | 2025-01 | 2025-04 |
Pricing and availability
| Gemini 2.5 Pro | o3 Mini | |
|---|---|---|
| Input price | $1.25/1M tokens | $1.1/1M tokens |
| Output price | $10/1M tokens | $4.4/1M tokens |
| Providers |
Capabilities
| Gemini 2.5 Pro | o3 Mini | |
|---|---|---|
| Vision | ||
| Multimodal | ||
| Reasoning | ||
| Function calling | ||
| Tool use | ||
| Structured outputs | ||
| Code execution |
Benchmarks
| Benchmark | Gemini 2.5 Pro | o3 Mini |
|---|---|---|
| MMLU PRO | 86.2 | 79.1 |
| Google-Proof Q&A | 86.4 | 79.7 |
| Chatbot Arena | 1398.0 | 1335.0 |
Deep dive
On shared benchmark coverage, MMLU PRO has Gemini 2.5 Pro at 86.2 and o3 Mini at 79.1, with Gemini 2.5 Pro ahead by 7.1 points; Google-Proof Q&A has Gemini 2.5 Pro at 86.4 and o3 Mini at 79.7, with Gemini 2.5 Pro ahead by 6.7 points; Chatbot Arena has Gemini 2.5 Pro at 1398 and o3 Mini at 1335, with Gemini 2.5 Pro ahead by 63 points. The largest visible gap is 63 points on Chatbot Arena, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.
The capability footprint differs most on vision: Gemini 2.5 Pro, multimodal input: Gemini 2.5 Pro, and reasoning mode: o3 Mini. Both models share function calling, tool use, structured outputs, and code execution, 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 2.5 Pro lists $1.25/1M input and $10/1M output tokens, while o3 Mini lists $1.1/1M input and $4.4/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts o3 Mini lower by about $1.79 per million blended tokens. Availability is 3 providers versus 3, so concentration risk also matters.
Choose Gemini 2.5 Pro when coding workflow support are central to the workload. Choose o3 Mini when coding workflow support and lower input-token cost are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.
FAQ
Which is cheaper, Gemini 2.5 Pro or o3 Mini?
o3 Mini is cheaper on tracked token pricing. Gemini 2.5 Pro costs $1.25/1M input and $10/1M output tokens. o3 Mini costs $1.1/1M input and $4.4/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Gemini 2.5 Pro or o3 Mini open source?
Gemini 2.5 Pro is listed under Proprietary. o3 Mini is listed under Unknown. 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 2.5 Pro or o3 Mini?
Gemini 2.5 Pro has the clearer documented vision signal in this comparison. If vision is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Which is better for multimodal input, Gemini 2.5 Pro or o3 Mini?
Gemini 2.5 Pro has the clearer documented multimodal input signal in this comparison. If multimodal input is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Which is better for reasoning mode, Gemini 2.5 Pro or o3 Mini?
o3 Mini has the clearer documented reasoning mode signal in this comparison. If reasoning mode is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Where can I run Gemini 2.5 Pro and o3 Mini?
Gemini 2.5 Pro is available on Google AI Studio, GCP Vertex AI, and OpenRouter. o3 Mini is available on OpenRouter, OpenAI Batch API, and Azure OpenAI. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-04-24. Data sourced from public model cards and provider documentation.