GPT-5.5 vs Gemini 3.1 Pro

How prompting differs between these two models.

GPT-5.5 benefits from explicit hierarchy and grounding rules. Gemini uses dedicated system instructions and long-context task placement.

Subjective side-by-side based on each model's official documentation. Not an empirical benchmark — see /research for measured results.

GPT-5.5

OpenAI · openai family

Strengths

extractionanalysisgenerationcode

Reach for it when…

API-first integrations
Structured JSON output
Function calling

GPT-5.5 prompting guide →

Gemini 3.1 Pro

Google · gemini family

Strengths

extractionanalysisgenerationlong-context-synthesis

Reach for it when…

Long documents (1M tokens)
Multimodal understanding
Google ecosystem integration

Gemini 3.1 Pro prompting guide →

How they differ in practice

Both are strong general-purpose models, but they respond to prompts differently. GPT-5.5 does best when hierarchy, constraints, and tool-use expectations are explicit. Gemini benefits from its dedicated systemInstruction field and careful long-context placement. Choose Gemini for long-context or multimodal Google workflows; GPT-5.5 for advanced OpenAI integrations and agentic work.

Try the same prompt on both.

Refrase rewrites your prompt for each model using its own documentation. Run it on GPT-5.5 and Gemini 3.1 Pro and compare the outputs side-by-side.

Try with GPT-5.5 Try with Gemini 3.1 Pro