Gemini 3 Pro vs o3 for coding
Gemini 3 Pro is the stronger coder of the two on benchmarks, but o3 can be the better pick when cost, speed, or context window matter more. Below: a side-by-side spec table and exactly when to pick each.
At a glance
| Spec | Gemini 3 Pro | o3 |
|---|---|---|
| Provider | OpenAI | |
| Released | Nov 2025 | Apr 2025 |
| SWE-bench Verified | 76% | 71% |
| HumanEval | 95% | 96% |
| MMLU | 92% | 91% |
| Context window | 1M+ | 200K |
| Max output | 64K | 100K |
| Input price (per 1M) | $2 | $10 |
| Output price (per 1M) | $12 | $40 |
| Price tier | Premium | Premium |
| Speed | Medium | Slow/Reasoning |
| Hosting | Closed/API | Closed/API |
| Modality | Multimodal (vision, audio, video) | Multimodal (vision) |
| Knowledge cutoff | Jan 2026 | Jun 2024 |
Pick Gemini 3 Pro if…
- It scores higher on SWE-bench Verified (76% vs 71%), the best proxy for real-world coding.
- It has a larger context window (1M+ vs 200K).
- It responds faster (Medium).
- It's tuned for long-horizon agentic tasks, generative UI, multi-modal reasoning, Antigravity-driven workflows.
Pick o3 if…
- It's tuned for hardest coding problems, complex multi-step reasoning, advanced debugging.
Gemini 3 Pro vs o3: which is better for coding?
Gemini 3 Pro is the stronger coder of the two on benchmarks, but o3 can be the better pick when cost, speed, or context window matter more. See the full spec table for SWE-bench, HumanEval, MMLU, context window, and pricing on both. Benchmarks are a directional signal, not a guarantee for your codebase — the most reliable test is running both on a real task you care about.
Compare these head-to-head with live data, or build a full stack around your pick — Flowpicker shows compatibility and monthly cost.
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See the full model leaderboard ranked by SWE-bench, HumanEval, and MMLU.