Gemini 3.1 Pro vs Gemini 3 Flash

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

Gemini 3.1 Pro by Google wins on 10 of 15 benchmarks against Gemini 3 Flash by Google, which leads on 4. 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 Gemini 3 Flash's 1473, while Gemini 3.1 Pro scores 92.6% on MMLU-Pro compared to Gemini 3 Flash's 88.6%, while Gemini 3.1 Pro scores 92.0% on IFEval compared to Gemini 3 Flash's 89.0%.

Coding: In coding, Gemini 3.1 Pro scores 93.0% on HumanEval+ compared to Gemini 3 Flash's 86.0%, while Gemini 3.1 Pro scores 80.6% on SWE-bench Verified compared to Gemini 3 Flash's 78.0%, while Gemini 3.1 Pro scores 75.0% on LiveCodeBench compared to Gemini 3 Flash's 55.0%.

Math: In math, Gemini 3.1 Pro scores 93.0% on MATH compared to Gemini 3 Flash's 85.0%, while Gemini 3.1 Pro scores 98.0% on GSM8K compared to Gemini 3 Flash's 95.0%.

Reasoning: In reasoning, Gemini 3.1 Pro scores 94.1% on GPQA Diamond compared to Gemini 3 Flash's 72.0%, while Gemini 3.1 Pro scores 77.1% on ARC-AGI compared to Gemini 3 Flash's 30.0%.

Context: In context, both score 1.0M on Context Length.

Pricing Comparison

Gemini 3.1 Pro costs $2.0/1M input tokens and $12.0/1M output tokens, while Gemini 3 Flash costs $0.50/1M input and $3.0/1M output. Gemini 3 Flash is the more affordable option for API usage.

Speed Comparison

Gemini 3.1 Pro generates output at 65 tok/s compared to Gemini 3 Flash's 200 tok/s, and the time to first token is 420 ms for Gemini 3.1 Pro versus 100 ms for Gemini 3 Flash. Gemini 3 Flash delivers faster throughput.

Verdict

For developers prioritizing coding and general intelligence and math, Gemini 3.1 Pro has the edge. For those who value affordability and speed, Gemini 3 Flash is the stronger choice.

Gemini 3.1 Pro vs Gemini 3 Flash — FAQ

Which is better, Gemini 3.1 Pro or Gemini 3 Flash?

Gemini 3.1 Pro wins on more benchmarks overall (10 vs 4). However, the best choice depends on your specific needs — each model excels in different areas.

How does Gemini 3.1 Pro compare to Gemini 3 Flash for coding?

Gemini 3.1 Pro is better for coding, scoring 80.6% on SWE-bench Verified compared to 78.0%. SWE-bench tests real-world software engineering by resolving actual GitHub issues.

Is Gemini 3.1 Pro cheaper than Gemini 3 Flash?

Yes, Gemini 3 Flash is cheaper. Gemini 3.1 Pro costs $2.0/1M input and $12.0/1M output tokens. Gemini 3 Flash costs $0.50/1M input and $3.0/1M output tokens.

Which is faster, Gemini 3.1 Pro or Gemini 3 Flash?

Gemini 3 Flash is faster, generating output at 200 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 Gemini 3 Flash comparison cover?

This comparison covers 15 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.