Gemini 3.1 Pro vs GPT-5.1

Side-by-side benchmark comparison across coding, math, reasoning, speed, and pricing.

Gemini 3.1 Pro by Google wins on 8 of 16 benchmarks against GPT-5.1 by OpenAI, which leads on 7. This head-to-head comparison covers coding, math, reasoning, speed, and pricing metrics from the AI Value Index.

Category-by-Category Breakdown

General Intelligence: In general intelligence, Gemini 3.1 Pro scores 1501 on Chatbot Arena ELO compared to GPT-5.1's 1464, while Gemini 3.1 Pro scores 92.6% on MMLU-Pro compared to GPT-5.1's 86.0%, while Gemini 3.1 Pro scores 92.0% on IFEval compared to GPT-5.1's 91.0%.

Coding: In coding, both score 93.0% on HumanEval+, while Gemini 3.1 Pro scores 80.6% on SWE-bench Verified compared to GPT-5.1's 76.3%, while GPT-5.1 scores 82.0% on LiveCodeBench compared to Gemini 3.1 Pro's 75.0%.

Math: In math, GPT-5.1 scores 95.0% on MATH compared to Gemini 3.1 Pro's 93.0%, while GPT-5.1 scores 98.5% on GSM8K compared to Gemini 3.1 Pro's 98.0%, while Gemini 3.1 Pro scores 95.0% on AIME 2025 compared to GPT-5.1's 94.0%.

Reasoning: In reasoning, Gemini 3.1 Pro scores 94.1% on GPQA Diamond compared to GPT-5.1's 88.1%, while Gemini 3.1 Pro scores 77.1% on ARC-AGI compared to GPT-5.1's 50.0%.

Context: In context, Gemini 3.1 Pro scores 1.0M on Context Length compared to GPT-5.1's 400K.

Pricing Comparison

Gemini 3.1 Pro costs $2.0/1M input tokens and $12.0/1M output tokens, while GPT-5.1 costs $1.3/1M input and $10.0/1M output. GPT-5.1 is the more affordable option for API usage.

Speed Comparison

Gemini 3.1 Pro generates output at 65 tok/s compared to GPT-5.1's 95 tok/s, and the time to first token is 420 ms for Gemini 3.1 Pro versus 350 ms for GPT-5.1. GPT-5.1 delivers faster throughput.

Verdict

For developers prioritizing coding and general intelligence, Gemini 3.1 Pro has the edge. For those who value math and affordability and speed, GPT-5.1 is the stronger choice.

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Gemini 3.1 Pro vs GPT-5.1 — FAQ

Which is better, Gemini 3.1 Pro or GPT-5.1?

Gemini 3.1 Pro wins on more benchmarks overall (8 vs 7). However, the best choice depends on your specific needs — each model excels in different areas.

How does Gemini 3.1 Pro compare to GPT-5.1 for coding?

Gemini 3.1 Pro is better for coding, scoring 80.6% on SWE-bench Verified compared to 76.3%. SWE-bench tests real-world software engineering by resolving actual GitHub issues.

Is Gemini 3.1 Pro cheaper than GPT-5.1?

Yes, GPT-5.1 is cheaper. Gemini 3.1 Pro costs $2.0/1M input and $12.0/1M output tokens. GPT-5.1 costs $1.3/1M input and $10.0/1M output tokens.

Which is faster, Gemini 3.1 Pro or GPT-5.1?

GPT-5.1 is faster, generating output at 95 tok/s compared to 65 tok/s. Faster output speed means shorter wait times for API responses.

What benchmarks does the Gemini 3.1 Pro vs GPT-5.1 comparison cover?

This comparison covers 16 benchmarks including Chatbot Arena ELO, MMLU-Pro, HumanEval+, IFEval, MATH, SWE-bench Verified, GPQA Diamond, Output Speed, and more. Metrics span general intelligence, coding, math, reasoning, speed, and cost categories.