Gemma 3 12B vs o3 Pro

Gemma 3 12B

Google DeepMind

Gemma 3 12B is a 12-billion-parameter open-weight model from Google DeepMind, released in March 2025 as part of the Gemma 3 series designed to bring multimodal reasoning to accessible hardware. The model supports both text and image inputs across a 128K token context window, extending the vision capabilities that defined the Gemma 3 generation compared to earlier text-only Gemma releases. It became widely adopted for domain-specific fine-tuning in research and enterprise settings where full multimodal capability was needed without the infrastructure demands of larger frontier models.

o3 Pro

OpenAI

OpenAI o3-pro, released by OpenAI in June 2025, is an extended reasoning model from the o3 family that applies more compute per response to deliver deeper, more thorough answers on complex problems. It features a 200K token context window, 100K maximum output tokens, and vision capabilities. o3-pro targets research-grade reasoning tasks, extended coding sessions, and applications where accuracy on difficult problems justifies higher inference cost and latency.