Claude Opus 5.5 vs Grok Build 0.1

Anthropic's newest flagship, and the first in its Claude 5.5 family. Anthropic positions Opus 5.5 to perform at the level of its most capable model on most work, while costing meaningfully less to run than the previous Opus. It reads text and images, holds a very large context, and reasons before every answer with adjustable effort. Anthropic calls it their daily driver for serious coding, computer use, and knowledge work, with its knowledge current to mid-2026.

xAI's coding model, purpose-built for autonomous software engineering rather than chat. Grok Build 0.1 acts as an engineering agent: it reasons through a problem, writes code, runs your terminal, checks for errors, and fixes its own mistakes in a loop. It reads text and images, always reasons before answering, and natively supports Model Context Protocol. Built for long-horizon coding that runs with little supervision, at a low cost, tuned for agent loops.