Gemini 2.5 Pro vs Gemini 3 Flash
Side-by-side benchmark comparison across coding, math, reasoning, speed, and pricing.
Gemini 3 Flash by Google wins on 9 of 16 benchmarks against Gemini 2.5 Pro by Google, which leads on 6. This head-to-head comparison covers coding, math, reasoning, speed, and pricing metrics from our benchmark data.
Category-by-Category Breakdown
General Intelligence: In general intelligence, Gemini 3 Flash scores 1473 on Chatbot Arena ELO compared to Gemini 2.5 Pro's 1465, while Gemini 3 Flash scores 88.6% on MMLU-Pro compared to Gemini 2.5 Pro's 84.0%, while Gemini 3 Flash scores 89.0% on IFEval compared to Gemini 2.5 Pro's 88.0%.
Coding: In coding, Gemini 2.5 Pro scores 89.0% on HumanEval+ compared to Gemini 3 Flash's 86.0%, while Gemini 3 Flash scores 78.0% on SWE-bench Verified compared to Gemini 2.5 Pro's 63.8%, while Gemini 2.5 Pro scores 58.0% on LiveCodeBench compared to Gemini 3 Flash's 55.0%.
Math: In math, Gemini 2.5 Pro scores 88.0% on MATH compared to Gemini 3 Flash's 85.0%, while Gemini 2.5 Pro scores 95.5% on GSM8K compared to Gemini 3 Flash's 95.0%.
Reasoning: In reasoning, Gemini 2.5 Pro scores 84.0% on GPQA Diamond compared to Gemini 3 Flash's 72.0%, while Gemini 2.5 Pro scores 48.0% on ARC-AGI compared to Gemini 3 Flash's 30.0%.
Context: In context, both score 1.0M on Context Length.
Pricing Comparison
Gemini 2.5 Pro costs $1.3/1M input tokens and $10.0/1M 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 2.5 Pro generates output at 55 tok/s compared to Gemini 3 Flash's 200 tok/s, and the time to first token is 500 ms for Gemini 2.5 Pro versus 100 ms for Gemini 3 Flash. Gemini 3 Flash delivers faster throughput.
Verdict
For developers prioritizing math, Gemini 2.5 Pro has the edge. For those who value coding and general intelligence and affordability and speed, Gemini 3 Flash is the stronger choice.
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Gemini 2.5 Pro vs Gemini 3 Flash — FAQ
Which is better, Gemini 2.5 Pro or Gemini 3 Flash?
Gemini 3 Flash wins on more benchmarks overall (9 vs 6). However, the best choice depends on your specific needs — each model excels in different areas.
How does Gemini 2.5 Pro compare to Gemini 3 Flash for coding?
Gemini 3 Flash is better for coding, scoring 78.0% on SWE-bench Verified compared to 63.8%. SWE-bench tests real-world software engineering by resolving actual GitHub issues.
Is Gemini 2.5 Pro cheaper than Gemini 3 Flash?
Yes, Gemini 3 Flash is cheaper. Gemini 2.5 Pro costs $1.3/1M input and $10.0/1M output tokens. Gemini 3 Flash costs $0.50/1M input and $3.0/1M output tokens.
Which is faster, Gemini 2.5 Pro or Gemini 3 Flash?
Gemini 3 Flash is faster, generating output at 200 tok/s compared to 55 tok/s. Faster output speed means shorter wait times for API responses.
What benchmarks does the Gemini 2.5 Pro vs Gemini 3 Flash comparison cover?
This comparison covers 16 benchmarks including Chatbot Arena ELO, MMLU-Pro, HumanEval+, IFEval, MATH, GPQA Diamond, SWE-bench Verified, Output Speed, and more. Metrics span general intelligence, coding, math, reasoning, speed, and cost categories.