Gemini 3 Flash vs o3
Gemini 3 Flash 
o3 Verdict
- Gemini 3 Flash (thinking) and o3 are level on quality (61.6 vs 61.6).
- Gemini 3 Flash (thinking) is stronger in composite, instruction following, knowledge, long context, multimodal.
- o3 is stronger in agents & tools, coding, human preference, maths, reasoning.
- Gemini 3 Flash (thinking) is 3.1× cheaper ($1.13 vs $3.50 per 1M blended).
- Gemini 3 Flash (thinking) streams 1.8× faster (192 vs 107 tokens per second).
| Metric | Gemini 3 Flash (thinking) | o3 |
|---|---|---|
| BenchLeader Index | 61.6 | 61.6 |
| Agents & tools score | 67.4 | 70.3 |
| Composite score | 62.3 | 54.5 |
| Instruction following score | 75.4 | 65.0 |
| Knowledge score | 69.1 | 58.0 |
| Long context score | 65.5 | 63.8 |
| Multimodal score | 64.5 | 57.9 |
| Coding score | – | 62.0 |
| Human preference score | – | 62.3 |
| Maths score | – | 78.6 |
| Reasoning score | – | 61.5 |
| Blended price $/M | $1.13 | $3.50 |
| Output speed | 192 tok/s | 107 tok/s |
| Time to first answer | 6.2 s | 6.3 s |
| Context window | 1M | 200k |
| Epoch Capabilities Index | – | 146.9 |
| LMArena Text | – | 1432 |
| LMArena Hard Prompts | – | 1441 |
| LMArena Coding | – | 1460 |
| LMArena Vision | – | 1214 |
| AA Intelligence Index | 26.3 | 20.2 |
| IFBench | 78.0% | 71.4% |
| AA-LCR | 78.0% | 74.7% |
| MMMU-Pro | 79.9% | 70.1% |
| AA-Omniscience | 10.1 | -15.6 |
| Terminal-Bench Hard | 38.6% | 37.1% |
| GPQA Diamond (AA) | 89.8% | 82.7% |
| Humanity's Last Exam (AA) | 36.6% | 20.1% |
| τ²-Bench Telecom (AA) | 80.4% | 80.7% |
| PRBench Finance | – | 47.7% |
| PRBench Legal | – | 48.6% |
| MMMU (validation) | – | 82.9% |
| MMMU-Pro (official) | – | 76.4% |
| Kagi LLM Benchmark | – | 67.6% |
| IFEval (HELM) | – | 86.9% |
| Omni-MATH (HELM) | – | 71.4% |
| WildBench (HELM) | – | 86.1% |
| MMLU-Pro (HELM) | – | 85.9% |
| GPQA Diamond (HELM) | – | 75.3% |
| HELM Capabilities mean | – | 81.1% |
| Aider Polyglot | – | 81.3% |
| SWE-bench Verified (bash only) | – | 58.4% |
| SWE-bench Verified (any scaffold) | – | 58.4% |
| BFCL Overall | – | 63.0% |
Data as of 2026-09-12. Best configuration of each model; every score links to its source on the model pages.
Gemini 3 Flash vs o3: questions
- Is Gemini 3 Flash better than o3?
- Gemini 3 Flash (thinking) and o3 are level on quality (61.6 vs 61.6). The BenchLeader Index combines every independent quality benchmark; o3 is ahead overall as of 2026-09-12, but check the category scores for your use.
- Is Gemini 3 Flash better than o3 for agentic tasks?
- o3 scores higher in agentic tasks (70 vs 67 on the category index, where 50 is average).
- Which is cheaper, Gemini 3 Flash or o3?
- Gemini 3 Flash is cheaper: $1.13 against $3.50 per million tokens, blended at three input tokens per output token.
- Which is faster, Gemini 3 Flash or o3?
- Gemini 3 Flash streams faster: 192 against 107 output tokens per second.
- Which has the larger context window?
- Gemini 3 Flash accepts more context: 1M against 200k tokens.