Objective comparison based on public benchmarks updated weekly: Intelligence Index, GPQA Diamond, Chatbot Arena ELO, pricing and speed.
Overall winner (2026)
GPT-5.5
5 of 7 criteria won
| Critério | Gemini 2.5 Pro | GPT-5.5 |
|---|---|---|
| Chatbot Arena ELO | — | — |
| Intelligence Index (AA) | 34.6 | 60.2 ✓ |
| Coding Index (AA) | 32.0 | 59.1 ✓ |
| GPQA Diamond | 84.4% | 94.0% ✓ |
| Input price ($/1M tok) | $1.25 ✓ | $5.00 |
| Output price ($/1M tok) | $10.00 ✓ | $30.00 |
| Context window | 1.0M tokens | 1.1M tokens ✓ |
| Speed (tokens/s) | — | 64 tok/s ✓ |
✓ = winner in this criterion • Source: Artificial Analysis, LMArena, official APIs • Updated weekly
Choosing between Gemini 2.5 Pro and GPT-5.5 depends on your use case, budget and technical requirements. Below, a practical guide based on benchmark data and each model's specifications.
Google · Multimodal
OpenAI · Multimodal
GPT-5.5 wins in 5 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. Gemini 2.5 Pro costs $1.25/1M input tokens, while GPT-5.5 costs $5/1M tokens — 300% more expensive. For high-volume projects, Gemini 2.5 Pro represents significant savings. Total cost also depends on output pricing and your application's usage pattern.
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.