Model comparison
Gemini 3 Pro Deep Think vs GPT-5.5
Head-to-head evidence from 2 shared benchmark results across 1 category. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Gemini 3 Pro Deep Think #45 (Estimated); GPT-5.5 #11 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Gemini 3 Pro Deep Think and GPT-5.5 share 2 comparable benchmark results. 1 of 8 categories are comparable. 0 results are unique to Gemini 3 Pro Deep Think; 51 to GPT-5.5.
Updated July 28, 2026- Shared results
- 2
- Gemini 3 Pro Deep Think only
- 0
- GPT-5.5 only
- 51
- Comparable categories
- 1 / 8
Pick GPT-5.5 if you want the stronger benchmark profile. Gemini 3 Pro Deep Think only becomes the better choice if you need the larger 2M context window.
Confidence note. This is a partial-evidence comparison with 2 shared benchmark results across 1 evidence category; 1 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
GPT-5.5 is clearly ahead on the BenchAlign aggregate, 72.04 to 60.5. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
GPT-5.5's sharpest advantage is in reasoning, where it averages 85 against 45.1. The single biggest benchmark swing on the page is ARC-AGI-2, 45.1% to 85%.
Gemini 3 Pro Deep Think gives you the larger context window at 2M, compared with 1M for GPT-5.5.
Category breakdown
Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.
| Category | Gemini 3 Pro Deep Think | Δ | GPT-5.5 |
|---|---|---|---|
| Reasoning | Gemini 3 Pro Deep Think45.1 | Margin→ 39.9 | GPT-5.585.0 |
| Agentic | Gemini 3 Pro Deep ThinkNot measured | MarginNo overlap | GPT-5.581.6 |
| Coding | Gemini 3 Pro Deep ThinkNot measured | MarginNo overlap | GPT-5.558.6 |
| Knowledge | Gemini 3 Pro Deep ThinkNot measured | MarginNo overlap | GPT-5.557.8 |
| Math | Gemini 3 Pro Deep ThinkNot measured | MarginNo overlap | GPT-5.547.6 |
| Multimodal | Gemini 3 Pro Deep ThinkNot measured | MarginNo overlap | GPT-5.570.4 |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
ARC-AGI-2
ReasoningA 45.1%B 85%Winner: GPT-5.5Δ 39.9ARC-AGI-2: Gemini 3 Pro Deep Think scored 45.1%; GPT-5.5 scored 85%. GPT-5.5 wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Gemini 3 Pro Deep Think | GPT-5.5 | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Gemini 3 Pro Deep ThinkNot available | GPT-5.5$5 input / $30 output | A complete price comparison is not available. |
| Generation speedtokens per second | Gemini 3 Pro Deep ThinkNot available | GPT-5.5Not available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Gemini 3 Pro Deep ThinkNot available | GPT-5.5Not available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Gemini 3 Pro Deep Think2M | GPT-5.51M | Gemini 3 Pro Deep Think lists the larger context window. |
Benchmark Deep Dive
Agentic19 benchmarks
| Benchmark | Gemini 3 Pro Deep Think | GPT-5.5 | Result |
|---|---|---|---|
| Terminal-Bench 2.0Source | — | 82% | Not comparable |
| CyberGymSource | — | 81.8% | Not comparable |
| BrowseCompSource | — | 84.4% | Not comparable |
| OSWorld-VerifiedSource | — | 78.7% | Not comparable |
| MCP AtlasSource | — | 75.3% | Not comparable |
| ToolathlonSource | — | 55.6% | Not comparable |
| τ²-bench resultsSource | — | 93.9% | Not comparable |
| AA Agentic IndexSource | — | 44.9% | Not comparable |
| APEX-Agents-AASource | — | 37.7% | Not comparable |
| GDPval-AASource | — | 49.6% | Not comparable |
| GDPval-AASource | — | 1491 | Not comparable |
| Gert LabsSource | — | 72.93% | Not comparable |
| ResearchClawBenchSource | — | 17.0% | Not comparable |
| OSWorld 2.0Source | — | 13.0% | Not comparable |
| JobBenchSource | — | 42.7% | Not comparable |
| ExploitGymSource | — | 13.4% | Not comparable |
| AA AutomationBenchSource | — | 42.1% | Not comparable |
| AA EnterpriseOps-GymSource | — | 46.6% | Not comparable |
| AA ITBenchSource | — | 45.8% | Not comparable |
Coding9 benchmarks
| Benchmark | Gemini 3 Pro Deep Think | GPT-5.5 | Result |
|---|---|---|---|
| SWE-bench ProSource | — | 58.6% | Not comparable |
| Terminal-Bench 2.0Source | — | 82.0% | Not comparable |
| Vibe Code BenchSource | — | 69.85% | Not comparable |
| React Native EvalsSource | — | 84.7% | Not comparable |
| cursorBench31Source | — | 59.2% | Not comparable |
| cursorBench32Source | — | 58.4% | Not comparable |
| AA Coding IndexSource | — | 74.9% | Not comparable |
| AA-SciCodeSource | — | 56.1% | Not comparable |
| FrontierCode 1.1 MainSource | — | 43.0% | Not comparable |
ReasoningGPT-5.5 wins6 benchmarks
Knowledge10 benchmarks
| Benchmark | Gemini 3 Pro Deep Think | GPT-5.5 | Result |
|---|---|---|---|
| GPQASource | — | 93.6% | Not comparable |
| GPQA-DSource | — | 93.6% | Not comparable |
| HLESource | — | 52.2% | Not comparable |
| HLE w/o toolsSource | — | 41.4% | Not comparable |
| Artificial Analysis Intelligence IndexSource | — | 54.8% | Not comparable |
| AA-GPQA DiamondSource | — | 93.5% | Not comparable |
| AA-HLESource | — | 44.3% | Not comparable |
| AA-Omniscience IndexSource | — | 20.1% | Not comparable |
| AA-Omniscience AccuracySource | — | 56.9% | Not comparable |
| AA-Omniscience Hallucination RateSource | — | 85.5% | Not comparable |
Math3 benchmarks
Multimodal5 benchmarks
Inst. Following1 benchmarks
| Benchmark | Gemini 3 Pro Deep Think | GPT-5.5 | Result |
|---|---|---|---|
| AA-IFBenchSource | — | 75.9% | Not comparable |
Frequently Asked Questions (2)
Which is better, Gemini 3 Pro Deep Think or GPT-5.5?
GPT-5.5 is ahead on BenchLM's BenchAlign leaderboard, 72.04 to 60.5. The biggest single separator in this matchup is ARC-AGI-2, where the scores are 45.1% and 85%.
Which is better for reasoning, Gemini 3 Pro Deep Think or GPT-5.5?
GPT-5.5 has the edge for reasoning in this comparison, averaging 85 versus 45.1. Inside this category, ARC-AGI-2 is the benchmark that creates the most daylight between them.
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