Claude Opus 4.6 vs Gemini 3.1 Pro

Claude Opus 4.6

Anthropic

Claude Opus 4.6, released by Anthropic in February 2026, is a large language model from the Claude 4 family designed for complex agent orchestration, extended reasoning, and long-form code generation. It features a 200K token context window (extendable to 1M tokens in beta), 128K maximum output tokens, native image understanding, and extended thinking with both standard and adaptive effort modes. Opus 4.6 targets multi-step agentic workflows, parallel tool use, and applications requiring sustained reasoning over large contexts.

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.