Gemini 3 Pro's launch, with a 1M-token context and top reasoning scores, was the trigger for OpenAI's 'code red' and the GPT-5.2 release weeks later. They're the defining frontier rivalry of the cycle. Gemini's strengths are scale and multimodality: it reasons over huge documents, codebases and video in a single pass, and it leads on many math, science and competitive-coding benchmarks.
GPT-5.2 answers with deeper agentic tool reliability, strong long-horizon reasoning and excellent professional document output, plus the breadth of the ChatGPT ecosystem. Where Gemini's 1M context is decisive for very large inputs, GPT-5.2's tool orchestration and artifact generation often win for agent workflows and business deliverables. On pure intelligence they're neck-and-neck, with the lead changing by benchmark.
Which should you choose?
GPT-5.2
GPT-5.2 · 400K context
Pick it if
you need agentic tool use, multimodal polish and document generation.
Gemini 3 Pro
Gemini 3 Pro
Pick it if
you need 1M-token context and the strongest multimodal reasoning.
Gemini 3 Pro wins for massive context and multimodal reasoning; GPT-5.2 wins for agentic tooling and document work. It's a true coin-flip at the top: let your workload decide.
Questions
Which has a bigger context window?
Gemini 3 Pro, with 1M tokens, far exceeds typical GPT-5.2 context limits, a major edge for very large inputs.
Which is better at coding?
Both are excellent; Gemini's huge context helps with whole-repo reasoning, while GPT-5.2-Codex is tuned for large, agentic code changes.