Objective comparison based on public benchmarks updated weekly: Intelligence Index, GPQA Diamond, Chatbot Arena ELO, pricing and speed.
| Critério | GPT-5.5 | Gemini 3.1 Pro Preview |
|---|---|---|
| Chatbot Arena ELO | — | — |
| Intelligence Index (AA) | 60.2 ✓ | 57.2 |
| Coding Index (AA) | 59.1 ✓ | 55.5 |
| GPQA Diamond | 94.0% | 94.0% |
| Input price ($/1M tok) | $5.00 | $2.00 ✓ |
| Output price ($/1M tok) | $30.00 | $12.00 ✓ |
| Context window | 1.1M tokens ✓ | 1.0M tokens |
| Speed (tokens/s) | 67 tok/s | 136 tok/s ✓ |
✓ = winner in this criterion • Source: Artificial Analysis, LMArena, official APIs • Updated weekly
Choosing between GPT-5.5 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
GPT-5.5 and Gemini 3.1 Pro Preview are evenly matched in this comparison. Choose based on the criterion most important for your project.
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.
No. Gemini 3.1 Pro Preview is cheaper: $2/1M input tokens vs $5/1M tokens for GPT-5.5 — a 150% difference. For high-volume projects, Gemini 3.1 Pro Preview can reduce costs substantially.
GPT-5.5 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.