Gemini 3.1 Pro vs o1 mini

Gemini 3.1 Pro

Google DeepMind

Gemini 3.1 Pro is a multimodal language model from Google DeepMind, released in preview in February 2026 as a point-version upgrade to Gemini 3 Pro focused on improving reasoning depth, factual grounding, and coding and agentic task performance. The model accepts text, images, video, audio, and PDFs as inputs across a 1M token context window, extending the multimodal breadth of the Gemini 3 series with a companion endpoint specifically optimized for custom tool use in agentic pipelines. Google describes it as built to refine the reliability and performance of the Gemini 3 Pro series, reflecting an incremental engineering iteration rather than an architectural overhaul.

o1 mini

OpenAI

OpenAI o1 mini, released by OpenAI in September 2024, is a lightweight reasoning model from the o1 family optimized for efficient STEM problem-solving at lower cost and latency. It features a 128K token context window and applies chain-of-thought reasoning specifically tuned for mathematics, science, and coding tasks. o1 mini targets use cases where rapid, cost-efficient reasoning is preferred over the broader capabilities of the full o1 model.