Gemini 2.5 Pro Preview 06-05 vs o3
Gemini 2.5 Pro Preview 06-05 (2025) and o3 (2025) are frontier reasoning models from Google DeepMind and OpenAI. Gemini 2.5 Pro Preview 06-05 ships a 1M-token context window, while o3 ships a 128K-token context window. On SWE-bench Verified, Gemini 2.5 Pro Preview 06-05 leads by 18.9 pts. On pricing, o3 costs $1/1M input tokens versus $1.25/1M for the alternative. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit.
Gemini 2.5 Pro Preview 06-05 fits 8x more tokens; pick it for long-context work and o3 for tighter calls.
Specs
| Released | 2025-03-25 | 2025-03-31 |
| Context window | 1M | 128K |
| Parameters | — | — |
| Architecture | decoder only | decoder only |
| License | Unknown | Unknown |
| Knowledge cutoff | - | - |
Pricing and availability
| Gemini 2.5 Pro Preview 06-05 | o3 | |
|---|---|---|
| Input price | $1.25/1M tokens | $1/1M tokens |
| Output price | $10/1M tokens | $4/1M tokens |
| Providers |
Capabilities
| Gemini 2.5 Pro Preview 06-05 | o3 | |
|---|---|---|
| Vision | ||
| Multimodal | ||
| Reasoning | ||
| Function calling | ||
| Tool use | ||
| Structured outputs | ||
| Code execution |
Benchmarks
| Benchmark | Gemini 2.5 Pro Preview 06-05 | o3 |
|---|---|---|
| SWE-bench Verified | 90.6 | 71.7 |
| Aider Polyglot | 79.1 | 81.3 |
Deep dive
On shared benchmark coverage, SWE-bench Verified has Gemini 2.5 Pro Preview 06-05 at 90.6 and o3 at 71.7, with Gemini 2.5 Pro Preview 06-05 ahead by 18.9 points; Aider Polyglot has Gemini 2.5 Pro Preview 06-05 at 79.1 and o3 at 81.3, with o3 ahead by 2.2 points. The largest visible gap is 18.9 points on SWE-bench Verified, 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 reasoning mode: o3. Both models share 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 Preview 06-05 lists $1.25/1M input and $10/1M output tokens, while o3 lists $1/1M input and $4/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts o3 lower by about $1.98 per million blended tokens. Availability is 1 providers versus 3, so concentration risk also matters.
Choose Gemini 2.5 Pro Preview 06-05 when coding workflow support and larger context windows are central to the workload. Choose o3 when coding workflow support, lower input-token cost, and broader provider choice 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 2.5 Pro Preview 06-05 or o3?
Gemini 2.5 Pro Preview 06-05 supports 1M tokens, while o3 supports 128K 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 2.5 Pro Preview 06-05 or o3?
o3 is cheaper on tracked token pricing. Gemini 2.5 Pro Preview 06-05 costs $1.25/1M input and $10/1M output tokens. o3 costs $1/1M input and $4/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Gemini 2.5 Pro Preview 06-05 or o3 open source?
Gemini 2.5 Pro Preview 06-05 is listed under Unknown. o3 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 reasoning mode, Gemini 2.5 Pro Preview 06-05 or o3?
o3 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.
Which is better for structured outputs, Gemini 2.5 Pro Preview 06-05 or o3?
Both Gemini 2.5 Pro Preview 06-05 and o3 expose structured outputs. 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 2.5 Pro Preview 06-05 and o3?
Gemini 2.5 Pro Preview 06-05 is available on OpenRouter. o3 is available on OpenAI API, OpenRouter, and OpenAI Batch API. 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.