whichLlmmodel
Back to Dashboard

GoogleGemini 3.5 FlashVSOpenAIGPT-5.5 Pro

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

Our Take

Standardized reasoning and coding benchmarks are currently pending verification for one or both of these models. We recommend testing Gemini 3.5 Flash and GPT-5.5 Pro directly in their respective provider playgrounds to see which fits your specific prompt styles best.
Was this recommendation helpful?
Model Specs

Gemini 3.5 Flash

Benchmarks & Scores

Coding (swe-bench-pro)
55.1%

complex codebases, multi-file repositories, and architectural planning

Reasoning (gpqa-diamond)
92.2%

graduate-level science QA

Cost & Context

Cost (per 1M tokens)20.0x cheaper
$3.38Input: $1.50 | Output: $9.00
Context Window
1.05M tokens
Model Specs

GPT-5.5 Pro

Benchmarks & Scores

Coding (swe-bench-pro)
N/A

complex codebases, multi-file repositories, and architectural planning

Reasoning (gpqa-diamond)Winner (+4.0%)
96.2%

graduate-level science QA

Cost & Context

Cost (per 1M tokens)
$67.50Input: $30.00 | Output: $180.00
Context WindowLarger
1.05M tokens

Frequently Asked Questions about Gemini 3.5 Flash vs GPT-5.5 Pro

Gemini 3.5 Flash is cheaper than GPT-5.5 Pro. Gemini 3.5 Flash has a blended cost of $3.38/1M tokens, which is about 20.0x cheaper than GPT-5.5 Pro at $67.50/1M tokens.

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