Gemini 3 Pro vs o3

Gemini 3 Pro

Google DeepMind

Gemini 3 Pro, released by Google in November 2025, is a large language model from the Gemini 3 family designed for complex reasoning, broad world knowledge, and multi-step problem solving. It features a 1M token context window, 64K maximum output tokens, and native multimodal input including text, images, audio, and video. Gemini 3 Pro targets research-grade reasoning, advanced data analysis, and applications requiring comprehensive understanding across diverse input formats.

o3

OpenAI

OpenAI o3, released by OpenAI in April 2025, is a large reasoning model that applies extended chain-of-thought processing to deliver improved performance on complex math, science, and coding tasks. It features a 200K token context window and native image understanding, with demonstrated strong results on mathematics and software engineering benchmarks. o3 targets demanding analytical and engineering tasks where deliberate, multi-step reasoning produces significantly better outcomes than direct generation.