Gemini 3 Pro vs GPT-5.5 Pro
Gemini 3 Pro 
GPT-5.5 Pro Verdict
- GPT-5.5 Pro (xhigh) leads on quality: 67.1 vs 61.1.
- Gemini 3 Pro is stronger in agents & tools, coding, human preference, instruction following, knowledge, multimodal.
- GPT-5.5 Pro (xhigh) is stronger in maths, reasoning.
- Gemini 3 Pro is 15× cheaper ($4.50 vs $67.50 per 1M blended).
| Metric | Gemini 3 Pro | GPT-5.5 Pro (xhigh) |
|---|---|---|
| BenchLeader Index | 61.1 | 67.1 |
| Agents & tools score | 61.4 | – |
| Coding score | 58.8 | – |
| Human preference score | 68.8 | – |
| Instruction following score | 61.9 | – |
| Knowledge score | 56.5 | – |
| Maths score | 54.8 | 74.5 |
| Multimodal score | 66.0 | – |
| Reasoning score | 67.1 | 80.1 |
| Blended price $/M | $4.50 | $67.50 |
| Output speed | – | 4 tok/s |
| Time to first answer | – | 3.5 s |
| Context window | 1.0M | 1.1M |
| GPQA Diamond | 92.6% | – |
| FrontierMath Tiers 1–3 | – | 87.7% |
| FrontierMath Tier 4 | – | 78.0% |
| OTIS Mock AIME | 91.4% | – |
| SWE-bench Verified (Epoch) | 72.9% | – |
| Humanity's Last Exam | 37.5% | – |
| Terminal-Bench | 69.4% | – |
| SimpleBench | 76.4% | – |
| GDPval | 40.3% | – |
| Remote Labor Index | 1.3% | – |
| WeirdML | 69.9% | – |
| APEX-Agents | 31.5% | – |
| ProofBench | 20.0% | – |
| GSO-Bench | 18.6% | – |
| Epoch Capabilities Index | 153 | – |
| LMArena Text | 1486 | – |
| LMArena Hard Prompts | 1504 | – |
| LMArena Coding | 1518 | – |
| LMArena WebDev | 1439 | – |
| LMArena Vision | 1304 | – |
| LiveCodeBench | 86.4% | – |
| MMLU-Pro | 90.1% | – |
| AIME 2026 | 91.7% | – |
| HMMT February 2026 | 86.4% | – |
| MathArena Apex | 23.4% | – |
| SWE-Bench Pro | 43.3% | – |
| MCP Atlas | 70.3% | – |
| MultiChallenge | 65.7% | – |
| PRBench Finance | 39.2% | – |
| PRBench Legal | 40.6% | – |
| VISTA | 51.5% | – |
| MultiNRC | 59.0% | – |
| TutorBench | 53.7% | – |
| MMMU-Pro (official) | 81.0% | – |
| Kagi LLM Benchmark | 80.1% | – |
| IFEval (HELM) | 87.6% | – |
| Omni-MATH (HELM) | 55.6% | – |
| WildBench (HELM) | 85.9% | – |
| MMLU-Pro (HELM) | 90.3% | – |
| GPQA Diamond (HELM) | 80.3% | – |
| HELM Capabilities mean | 79.9% | – |
| SWE-bench Verified (bash only) | 74.2% | – |
| SWE-bench Verified (any scaffold) | 77.4% | – |
| ARC-AGI-1 | 75.0% | 95.0% |
| ARC-AGI-2 | 54.0% | 84.2% |
| BFCL Overall | 72.5% | – |
| CritPt | – | 30.6% |
| Poker Agent | 1078.9% | – |
| FORTRESS | 41.7% | – |
| MASK | 42.6% | – |
| PropensityBench | 52.9% | – |
| SciPredict | 25.3% | – |
| SWE-Bench Pro (private) | 17.9% | – |
| VTB | 26.9% | – |
| LMArena Maths | 1477 | – |
| LMArena Creative Writing | 1483 | – |
| LMArena Instruction Following | 1473 | – |
| LMArena Multi-turn | 1495 | – |
| LMArena Longer Queries | 1491 | – |
| LMArena Document | 1451 | – |
| Chess Puzzles | 31.0% | – |
| BALROG | 58.1% | – |
| GeoBench | 84.0% | – |
| VPCT | 91.0% | – |
| CL-bench | 15.8% | – |
| METR Time Horizons | 71.0% | – |
| LMCA | – | 53.9% |
| DTBench | – | 96.0% |
| ForecastBench | 61.2% | – |
| ALE-Bench | 1176.8 | – |
| AlgoTune | 1.8 | – |
| Vending-Bench 2 | 5478.2 | – |
Data as of 2026-09-19. Best configuration of each model; every score links to its source on the model pages.
Gemini 3 Pro vs GPT-5.5 Pro: questions
- Is Gemini 3 Pro better than GPT-5.5 Pro?
- GPT-5.5 Pro (xhigh) leads on quality: 67.1 vs 61.1. The BenchLeader Index combines every independent quality benchmark; GPT-5.5 Pro (xhigh) is ahead overall as of 2026-09-19, but check the category scores for your use.
- Which is cheaper, Gemini 3 Pro or GPT-5.5 Pro?
- Gemini 3 Pro is cheaper: $4.50 against $67.50 per million tokens, blended at three input tokens per output token.
- Which has the larger context window?
- GPT-5.5 Pro accepts more context: 1.1M against 1.0M tokens.