Gemini 3.1 Flash Lite vs GPT-5.5 Pro: side-by-side summary

Gemini 3.1 Flash Lite and GPT-5.5 Pro are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.

Gemini 3.1 Flash Lite, from Google, has a 1,048,576-token context window and is priced at $0.25/M tokens input, $1.50/M tokens output on OpenRouter.

GPT-5.5 Pro, from OpenAI, has a 1,050,000-token context window and is priced at $30/M tokens input, $180/M tokens output on OpenRouter.

Context window

• Gemini 3.1 Flash Lite: 1,048,576 tokens
• GPT-5.5 Pro: 1,050,000 tokens

Price

• Gemini 3.1 Flash Lite: $0.25/M tokens input, $1.50/M tokens output
• GPT-5.5 Pro: $30/M tokens input, $180/M tokens output

Provided by

• Gemini 3.1 Flash Lite: Google
• GPT-5.5 Pro: OpenAI

• Gemini 3.1 Flash Lite model details, providers and pricing
• GPT-5.5 Pro model details, providers and pricing