Gemini 3 Pro vs GPT-5.1

Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.

Gemini 3 Pro

Google · Nov 2025

73.6

Google's November 2025 frontier breakout — 91.9% GPQA Diamond and 37.5% HLE made it the reasoning leader of its generation.

GPT-5.1

OpenAI · Nov 2025

59.6

A November 2025 update to GPT-5 with adaptive reasoning that spends thinking tokens only when a task needs them.

The verdict

Gemini 3 Pro wins 3 of the 4 benchmarks these models share, against 1 for GPT-5.1. GPT-5.1 is about 1.3x cheaper per blended million tokens (3:1 input:output mix). Gemini 3 Pro also takes 1M of context versus 400K for GPT-5.1.

Benchmark head-to-head 31

SWE-bench Verified
76.2%76.3%
Gemini 3 ProGPT-5.1
GPQA Diamond
91.9%~88.1%
Gemini 3 ProGPT-5.1
HLE
37.5%~26.5%
Gemini 3 ProGPT-5.1
Terminal-Bench
54.2%~47.6%
Gemini 3 ProGPT-5.1

Specs & pricing

Gemini 3 ProGPT-5.1
modhub Index73.659.6
Input price / 1M$2$1.25
Output price / 1M$12$10
Context window1M400K
Max output66K128K
Open weightsnono
Reasoning modelyesyes
Multimodal inputtext, image, audio, videotext, image
Knowledge cutoffJan 2025Sep 2024
ReleasedNov 2025Nov 2025
Example monthly cost*$38.00$27.50

* 10M input + 1.5M output tokens per month at list prices, no caching. Green = better value on that row.

Frequently asked questions

Which is better, Gemini 3 Pro or GPT-5.1?
Gemini 3 Pro wins 3 of the 4 benchmarks these models share, against 1 for GPT-5.1. GPT-5.1 is about 1.3x cheaper per blended million tokens (3:1 input:output mix). Gemini 3 Pro also takes 1M of context versus 400K for GPT-5.1.
Which is cheaper, Gemini 3 Pro or GPT-5.1?
Gemini 3 Pro costs $2/$12 per million input/output tokens, while GPT-5.1 costs $1.25/$10. For a typical workload of 10M input and 1.5M output tokens per month, that's $38.00 versus $27.50.
Which model is better for coding, Gemini 3 Pro or GPT-5.1?
On SWE-bench Verified — the standard agentic-coding benchmark — GPT-5.1 scores 76.3% versus 76.2% for Gemini 3 Pro, making GPT-5.1 the stronger pick for coding agents.

More comparisons