Gemini 3.5 Flash vs GPT-5.5

Google's Gemini 3.5 Flash against OpenAI's GPT-5.5 — price, context and what each is best at. Both are available through one OpenAI-compatible API.

AnyModel — you pay	Gemini 3.5 Flash	GPT-5.5
Vendor	Google	OpenAI
Input / 1M	$0.03	$0.05
Output / 1M	$0.03	$0.05
Context	1M	1M
Best for	Agents	Complex coding

Gemini 3.5 Flash

Google's newest default — frontier smarts at a Flash price.

Gemini 3.5 Flash is Google's freshest GA model: it beats Gemini 3.1 Pro on agentic and coding benchmarks while running about 4× faster, with selectable thinking levels and a 1M-token window — the new default pick of the Gemini line.

More about Gemini 3.5 Flash →

GPT-5.5

OpenAI's flagship for coding, agents and research-grade reasoning.

GPT-5.5 is OpenAI's top general-purpose model and the engine behind modern Codex: state-of-the-art coding, computer use and multi-step reasoning with a ~1M-token window. The default pick when you want one model that handles everything.

More about GPT-5.5 →

Quick take: Gemini 3.5 Flash is cheaper on output tokens ($0.03 vs $0.05 per 1M). Compare their strengths and context for your task; you can switch the model id at any time.

FAQ

Which is cheaper, Gemini 3.5 Flash or GPT-5.5?

Gemini 3.5 Flash is cheaper on output tokens ($0.03 vs $0.05 per 1M).

Which has a larger context window, Gemini 3.5 Flash or GPT-5.5?

Gemini 3.5 Flash: 1M; GPT-5.5: 1M.