tokevenGPT 5.1 vs Gemini 3.1 Pro Custom Tools
Side-by-side comparison of pricing, task quality, and projected cost at higher scale.
Pricing
Side-by-side pricing
GPT 5.1
Mid-tierGemini 3.1 Pro Custom Tools
Mid-tierQuality
Task confidence comparison
Guidance
When to use GPT 5.1 vs Gemini 3.1 Pro Custom Tools
Choose GPT 5.1 when...
- -Cost matters: 38% cheaper on input tokens
Choose Gemini 3.1 Pro Custom Tools when...
- -You need a larger context window (1,048.576K vs 272K)
- Similar performance; consider provider preference or ecosystem fit.
At scale
Cost at scale
FAQ
When should I use GPT 5.1 instead of Gemini 3.1 Pro Custom Tools?
GPT 5.1 and Gemini 3.1 Pro Custom Tools perform similarly across all tracked tasks. Pick based on pricing and provider preference.
Is Gemini 3.1 Pro Custom Tools cheaper than GPT 5.1?
Gemini 3.1 Pro Custom Tools input costs $2.00/MTok, which is 60% more than GPT 5.1 at $1.25/MTok.
What are the context window sizes for GPT 5.1 and Gemini 3.1 Pro Custom Tools?
GPT 5.1 has a 272K token context window. Gemini 3.1 Pro Custom Tools has a 1,048.576K token context window.
Go deeper on either model
Per-call cost calculators, provider lineups, and price history for both models on this page.
Other comparisons
How GPT 5.1 and Gemini 3.1 Pro Custom Tools stack up against the rest of the field.
Track your real costs
Comparisons show estimated costs at list price. The dashboard reveals your real spend and savings.