Objective comparison based on public benchmarks updated weekly: Intelligence Index, GPQA Diamond, Chatbot Arena ELO, pricing and speed.
Overall winner (2026)
Gemini 3.1 Pro Preview
4 of 7 criteria won
Intelligence Index
57.2
Coding Index
55.5
4 criteria won
View full profile →| Critério | GPT-5.5 Pro | Gemini 3.1 Pro Preview |
|---|---|---|
| Chatbot Arena ELO | — | — |
| Intelligence Index (AA) | — | 57.2 ✓ |
| Coding Index (AA) | — | 55.5 ✓ |
| GPQA Diamond | — | 94.0% ✓ |
| Input price ($/1M tok) | — ✓ | $2.00 |
| Output price ($/1M tok) | — ✓ | $12.00 |
| Context window | 1.1M tokens ✓ | 1.0M tokens |
| Speed (tokens/s) | — | 136 tok/s ✓ |
✓ = winner in this criterion • Source: Artificial Analysis, LMArena, official APIs • Updated weekly
Choosing between GPT-5.5 Pro and Gemini 3.1 Pro Preview depends on your use case, budget and technical requirements. Below, a practical guide based on benchmark data and each model's specifications.
OpenAI · Multimodal
Google · Multimodal
Gemini 3.1 Pro Preview wins in 4 of 7 criteria analyzed. Check the full table to choose based on your use case.
Data is aggregated from Artificial Analysis (Intelligence Index, Coding Index) and Chatbot Arena/LMArena (ELO). Pricing and specs come from official APIs. Updated weekly.
The Intelligence Index is an aggregate score from Artificial Analysis that combines multiple academic benchmarks (MMLU, GPQA, LiveBench, etc.) into a single rating. The higher the score, the more capable the model is at reasoning tasks.
Yes. GPT-5.5 Pro costs $0/1M input tokens, while Gemini 3.1 Pro Preview costs $2/1M tokens — Infinity% more expensive. For high-volume projects, GPT-5.5 Pro represents significant savings. Total cost also depends on output pricing and your application's usage pattern.
GPT-5.5 Pro has the larger context window: 1.1M tokens vs 1.0M tokens. For long document analysis, extensive transcripts or full codebases, the larger context window is a decisive criterion.