Gemini 2.5 Pro vs GPT-OSS 120B

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

Gemini 2.5 Pro by Google and GPT-OSS 120B by OpenAI are evenly matched across 12 benchmarks. 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 2.5 Pro scores 16.7 on AA Intelligence Index compared to GPT-OSS 120B's 12.3.

Coding: In coding, Gemini 2.5 Pro scores 33.3 on AA Coding Index compared to GPT-OSS 120B's 30.4, while Gemini 2.5 Pro scores 1164 on Design Arena ELO compared to GPT-OSS 120B's 974, while Gemini 2.5 Pro scores 1179 on Website Arena ELO compared to GPT-OSS 120B's 980.

Reasoning: In reasoning, Gemini 2.5 Pro scores 79.9% on GPQA Diamond compared to GPT-OSS 120B's 74.9%, while GPT-OSS 120B scores 6.2 on AA Agentic Index compared to Gemini 2.5 Pro's 3.5, while GPT-OSS 120B scores 64.1% on τ²-Bench Airline compared to Gemini 2.5 Pro's 61.3%.

Context: In context, Gemini 2.5 Pro scores 1.0M on Context Length compared to GPT-OSS 120B's 131K.

Pricing Comparison

Gemini 2.5 Pro costs $1.3/1M input tokens and $10.0/1M output tokens, while GPT-OSS 120B costs $0.04/1M input and $0.17/1M output. GPT-OSS 120B is the more affordable option for API usage.

Speed Comparison

Gemini 2.5 Pro generates output at 55 tok/s compared to GPT-OSS 120B's 339 tok/s, and the time to first token is 500 ms for Gemini 2.5 Pro versus 440 ms for GPT-OSS 120B. GPT-OSS 120B delivers faster throughput.

Verdict

GPT-OSS 120B leads across the board in affordability, speed, making it the stronger overall choice in this comparison.

Gemini 2.5 Pro vs GPT-OSS 120B — FAQ

Which is better, Gemini 2.5 Pro or GPT-OSS 120B?

Gemini 2.5 Pro and GPT-OSS 120B are evenly matched across benchmarks. The best choice depends on your specific priorities such as coding ability, speed, or pricing.

How does Gemini 2.5 Pro compare to GPT-OSS 120B for coding?

SWE-bench Verified data is not available for both models. Check the detailed comparison charts above for other coding-related metrics.

Is Gemini 2.5 Pro cheaper than GPT-OSS 120B?

Yes, GPT-OSS 120B is cheaper. Gemini 2.5 Pro costs $1.3/1M input and $10.0/1M output tokens. GPT-OSS 120B costs $0.04/1M input and $0.17/1M output tokens.

Which is faster, Gemini 2.5 Pro or GPT-OSS 120B?

GPT-OSS 120B is faster, generating output at 339 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 GPT-OSS 120B comparison cover?

This comparison covers 12 benchmarks including GPQA Diamond, Output Speed, Time to First Token, Input Cost, Output Cost, Context Length, AA Intelligence Index, AA Coding Index, and more. Metrics span general intelligence, coding, math, reasoning, speed, and cost categories.