Model comparison
Gemini 3.1 Pro vs GPT-5.5
Head-to-head evidence from 35 shared benchmark results across 7 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Gemini 3.1 Pro #83 (Estimated); GPT-5.5 #9 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Gemini 3.1 Pro and GPT-5.5 share 35 comparable benchmark results. 3 of 8 categories are comparable. 12 results are unique to Gemini 3.1 Pro; 22 to GPT-5.5.
Updated July 23, 2026- Shared results
- 35
- Gemini 3.1 Pro only
- 12
- GPT-5.5 only
- 22
- Comparable categories
- 3 / 8
Pick GPT-5.5 if you want the stronger benchmark profile. Gemini 3.1 Pro only becomes the better choice if multimodal & grounded is the priority or you want the cheaper token bill.
Confidence note. This is a partial-evidence comparison with 35 shared benchmark results across 7 evidence categories; 3 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, 73.51 to 55.3. 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 mathematics, where it averages 47.6 against 31.8. The single biggest benchmark swing on the page is FrontierMath v2 (Tier 4), 16.700% to 35.400%. Gemini 3.1 Pro does hit back in multimodal & grounded, so the answer changes if that is the part of the workload you care about most.
GPT-5.5 is also the more expensive model on tokens at $5.00 input / $30.00 output per 1M tokens, versus $2.00 input / $12.00 output per 1M tokens for Gemini 3.1 Pro. That is roughly 2.5x on output cost alone. GPT-5.5 is the reasoning model in the pair, while Gemini 3.1 Pro is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use.
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 3.1 Pro | Δ | GPT-5.5 |
|---|---|---|---|
| Math | Gemini 3.1 Pro31.8 | Margin→ 15.8 | GPT-5.547.6 |
| Multimodal | Gemini 3.1 Pro82.6 | Margin← 12.2 | GPT-5.570.4 |
| Reasoning | Gemini 3.1 Pro77.1 | Margin→ 7.9 | GPT-5.585.0 |
| Agentic | Gemini 3.1 ProNot measured | MarginNo overlap | GPT-5.581.6 |
| Coding | Gemini 3.1 ProNot measured | MarginNo overlap | GPT-5.558.6 |
| Knowledge | Gemini 3.1 ProNot measured | MarginNo overlap | GPT-5.557.8 |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
FrontierMath v2 (Tier 4)
MathA 16.700%B 35.400%Winner: GPT-5.5Δ 18.7FrontierMath v2 (Tier 4): Gemini 3.1 Pro scored 16.700%; GPT-5.5 scored 35.400%. GPT-5.5 wins this benchmark. - Source ↗
FrontierMath v2 (Tiers 1-3)
MathA 36.900%B 51.700%Winner: GPT-5.5Δ 14.8FrontierMath v2 (Tiers 1-3): Gemini 3.1 Pro scored 36.900%; GPT-5.5 scored 51.700%. GPT-5.5 wins this benchmark. - Source ↗
ARC-AGI-2
ReasoningA 77.1%B 85%Winner: GPT-5.5Δ 7.9ARC-AGI-2: Gemini 3.1 Pro scored 77.1%; GPT-5.5 scored 85%. GPT-5.5 wins this benchmark. - Source ↗
MMMU-Pro
MultimodalA 83.9%B 81.2%Winner: Gemini 3.1 ProΔ 2.7MMMU-Pro: Gemini 3.1 Pro scored 83.9%; GPT-5.5 scored 81.2%. Gemini 3.1 Pro wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Gemini 3.1 Pro | GPT-5.5 | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Gemini 3.1 Pro$2 input / $12 output | GPT-5.5$5 input / $30 output | Gemini 3.1 Pro has the lower combined listed price. |
| Generation speedtokens per second | Gemini 3.1 Pro109 tok/s | GPT-5.5Not available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Gemini 3.1 Pro29.71 s | GPT-5.5Not available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Gemini 3.1 Pro1M | GPT-5.51M | Listed context windows are equal. |
Benchmark Deep Dive
Agentic26 benchmarks
| Benchmark | Gemini 3.1 Pro | GPT-5.5 | Result |
|---|---|---|---|
| Claw-EvalSource | 57.8% | — | Not comparable |
| DeepSearchQASource | 69.7% | — | Not comparable |
| τ²-bench resultsSource | 95.6% | 93.9% | Gemini 3.1 Pro leads |
| AA Agentic IndexSource | 21.4% | 44.9% | GPT-5.5 leads |
| APEX-Agents-AASource | 32.0% | 37.7% | GPT-5.5 leads |
| GDPval-AASource | 23.3% | 49.5% | GPT-5.5 leads |
| GDPval-AASource | 965 | 1490 | GPT-5.5 leads |
| Gert LabsSource | 56.87% | 72.93% | GPT-5.5 leads |
| ResearchClawBenchSource | 13.3% | 17.0% | GPT-5.5 leads |
| AA AutomationBenchSource | 37.5% | 42.1% | GPT-5.5 leads |
| AA EnterpriseOps-GymSource | 42.2% | 46.6% | GPT-5.5 leads |
| AA Harvey LABSource | 58.9% | 86.3% | GPT-5.5 leads |
| AA ITBenchSource | 30.3% | 45.8% | GPT-5.5 leads |
| AA Tau3 BankingSource | 16.5% | 31.3% | GPT-5.5 leads |
| terminalBenchHardSource | 53.8% | 60.6% | GPT-5.5 leads |
| aaTerminalBench21Source | 73.8% | 84.3% | GPT-5.5 leads |
| 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 |
| OSWorld 2.0Source | — | 13.0% | Not comparable |
| JobBenchSource | — | 42.7% | Not comparable |
| ExploitGymSource | — | 13.4% | Not comparable |
| AA BriefcaseSource | — | 1154 | Not comparable |
Coding10 benchmarks
| Benchmark | Gemini 3.1 Pro | GPT-5.5 | Result |
|---|---|---|---|
| LiveCodeBench ProSource | 82.9% | — | Not comparable |
| React Native EvalsSource | 78.9% | 84.7% | GPT-5.5 leads |
| Vibe Code BenchSource | 32.03% | 69.85% | GPT-5.5 leads |
| AA Coding IndexSource | 68.8% | 74.9% | GPT-5.5 leads |
| AA-SciCodeSource | 58.9% | 56.1% | Gemini 3.1 Pro leads |
| SWE-bench ProSource | — | 58.6% | Not comparable |
| Terminal-Bench 2.0Source | — | 82.0% | Not comparable |
| cursorBench31Source | — | 59.2% | Not comparable |
| cursorBench32Source | — | 58.4% | Not comparable |
| FrontierCode 1.1 MainSource | — | 43.0% | Not comparable |
ReasoningGPT-5.5 wins5 benchmarks
Knowledge12 benchmarks
| Benchmark | Gemini 3.1 Pro | GPT-5.5 | Result |
|---|---|---|---|
| GPQA-DSource | 94.3% | 93.6% | Gemini 3.1 Pro leads |
| HLE w/o toolsSource | 45.4% | 41.4% | Gemini 3.1 Pro leads |
| HealthBench HardSource | 20.6% | — | Not comparable |
| MedXpertQA (Text)Source | 71.5% | — | Not comparable |
| Artificial Analysis Intelligence IndexSource | 46.5% | 54.8% | GPT-5.5 leads |
| AA-GPQA DiamondSource | 94.1% | 93.5% | Gemini 3.1 Pro leads |
| AA-HLESource | 44.7% | 44.3% | Gemini 3.1 Pro leads |
| AA-Omniscience IndexSource | 32.9% | 20.1% | Gemini 3.1 Pro leads |
| AA-Omniscience AccuracySource | 55.3% | 56.9% | GPT-5.5 leads |
| AA-Omniscience Hallucination RateSource | 49.9% | 85.5% | Gemini 3.1 Pro leads |
| GPQASource | — | 93.6% | Not comparable |
| HLESource | — | 52.2% | Not comparable |
MathGPT-5.5 wins3 benchmarks
Multilingual1 benchmarks
| Benchmark | Gemini 3.1 Pro | GPT-5.5 | Result |
|---|---|---|---|
| AA Global-MMLU-LiteSource | 93.2% | — | Not comparable |
MultimodalGemini 3.1 Pro wins11 benchmarks
| Benchmark | Gemini 3.1 Pro | GPT-5.5 | Result |
|---|---|---|---|
| MMMU-ProSource | 83.9% | 81.2% | Gemini 3.1 Pro leads |
| CharXivSource | 80.2% | — | Not comparable |
| ERQASource | 69.4% | — | Not comparable |
| SimpleVQASource | 72.4% | — | Not comparable |
| ScreenSpot ProSource | 84.4% | — | Not comparable |
| ZeroBenchSource | 29.0% | — | Not comparable |
| MedXpertQA (MM)Source | 81.3% | — | Not comparable |
| AA-MMMU-ProSource | 82.4% | 79.9% | Gemini 3.1 Pro leads |
| Design Arena WebsiteSource | 1281 | 1282 | GPT-5.5 leads |
| MMMU-Pro w/ PythonSource | — | 83.2% | Not comparable |
| OfficeQA ProSource | — | 54.1% | Not comparable |
Inst. Following1 benchmarks
| Benchmark | Gemini 3.1 Pro | GPT-5.5 | Result |
|---|---|---|---|
| AA-IFBenchSource | 77.1% | 75.9% | Gemini 3.1 Pro leads |
Frequently Asked Questions (4)
Which is better, Gemini 3.1 Pro or GPT-5.5?
GPT-5.5 is ahead on BenchLM's BenchAlign leaderboard, 73.51 to 55.3. The biggest single separator in this matchup is FrontierMath v2 (Tier 4), where the scores are 16.700% and 35.400%.
Which is better for math, Gemini 3.1 Pro or GPT-5.5?
GPT-5.5 has the edge for math in this comparison, averaging 47.6 versus 31.8. Inside this category, FrontierMath v2 (Tier 4) is the benchmark that creates the most daylight between them.
Which is better for reasoning, Gemini 3.1 Pro or GPT-5.5?
GPT-5.5 has the edge for reasoning in this comparison, averaging 85 versus 77.1. Inside this category, CritPt is the benchmark that creates the most daylight between them.
Which is better for multimodal and grounded tasks, Gemini 3.1 Pro or GPT-5.5?
Gemini 3.1 Pro has the edge for multimodal and grounded tasks in this comparison, averaging 82.6 versus 70.4. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.
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