GoogleGemini 2.5 ProVSOpenAIGPT-5.5

Analysis by:the whichllmmodel Editorial Team|Updated: June 2026

Our Take

These models use different coding evaluation benchmarks — with Gemini 2.5 Pro evaluated on swe-bench-verified (good at editing existing code, cross-file updates, and multi-component systems) and GPT-5.5 on swe-bench-pro (excellent at multi-file repositories, autonomous agents, and industrial codebases) — but GPT-5.5 holds a clear reasoning advantage (+9.2% on GPQA Diamond). However, Gemini 2.5 Pro is a massive 3.3x cheaper to run. Choose GPT-5.5 for complex logic and reasoning tasks, or Gemini 2.5 Pro to optimize your budget for high-volume pipelines.

Was this recommendation helpful?

Model Specs

Gemini 2.5 Pro

Website

Benchmarks & Scores

Coding (swe-bench-verified)

59.6%

good at editing existing code, cross-file updates, and multi-component systems

Reasoning (gpqa-diamond)

84.4%

graduate-level science QA

Cost & Context

Cost (per 1M tokens)3.3x cheaper

$3.44Input: $1.25 | Output: $10.00

Context Window

1.05M tokens

Model Specs

GPT-5.5

Website

Benchmarks & Scores

Coding (swe-bench-pro)

58.6%

excellent at multi-file repositories, autonomous agents, and industrial codebases

Reasoning (gpqa-diamond)Winner (+9.2%)

93.6%

graduate-level science QA

Cost & Context

Cost (per 1M tokens)

$11.25Input: $5.00 | Output: $30.00

Context WindowLarger

1.05M tokens

Read our data collection methodology

Frequently Asked Questions about Gemini 2.5 Pro vs GPT-5.5

Gemini 2.5 Pro is cheaper than GPT-5.5. Gemini 2.5 Pro has a blended cost of $3.44/1M tokens, which is about 3.3x cheaper than GPT-5.5 at $11.25/1M tokens.

For coding tasks, Gemini 2.5 Pro scores 59.6% on swe-bench-verified (good at editing existing code, cross-file updates, and multi-component systems), while GPT-5.5 scores 58.6% on swe-bench-pro (excellent at multi-file repositories, autonomous agents, and industrial codebases).

Related Matchups

Explore similar comparisons for Gemini 2.5 Pro and GPT-5.5.

Browse More Comparisons

Do you want to find a model for your constraints?

Use our interactive model finder to filter LLMs by reasoning capability, coding performance, cost, and context length.

Open Model Finder