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Gemini 2.5 Flash vs o3
A detailed comparison of Gemini 2.5 Flash (Google) and o3 (OpenAI) across pricing, performance, and features.
Pricing Comparison
| Metric | Gemini 2.5 Flash | o3 | Difference |
|---|---|---|---|
| Input / 1M tokens | $0.15 | $0.40 | +167% |
| Output / 1M tokens | $0.60 | $1.60 | +167% |
| Context window | 1M | 200K | — |
| Max output | 65.536K | 100K | — |
Benchmark Comparison
| Benchmark | Gemini 2.5 Flash | o3 |
|---|---|---|
| MMLU-Pro | 76% | 87% |
| HumanEval | 89.5% | 94.5% |
| GPQA | — | 79.2% |
Capabilities
| Capability | Gemini 2.5 Flash | o3 |
|---|---|---|
| code | ✓ | ✓ |
| reasoning | ✓ | ✓ |
| text | ✓ | ✓ |
| tool-use | ✓ | ✓ |
| vision | ✓ | ✓ |
Gemini 2.5 Flash Strengths
- ✓One of the cheapest models available
- ✓1M context at budget pricing
- ✓Free tier available
Gemini 2.5 Flash Weaknesses
- ✗Weaker than Flash 3 on most benchmarks
- ✗Output quality inconsistent on edge cases
o3 Strengths
- ✓Recently repriced — now very cheap
- ✓Excellent logical reasoning
- ✓200K context window
o3 Weaknesses
- ✗Slower due to reasoning overhead
- ✗Overkill for simple tasks
Quick Verdict
Best value: Gemini 2.5 Flash is the more affordable option at $0.15/$0.6 per 1M tokens.
Higher benchmarks: o3 scores higher on average across available benchmarks (86.9% avg).
Larger context: Gemini 2.5 Flash supports 1M tokens.
Choose Gemini 2.5 Flash if cost matters most. Choose o3 if you need the best possible quality for complex tasks.