GLM-5.1 vs Grok Build 0.1

Z.ai's flagship for agentic engineering, built to keep working rather than answer quickly. Z.ai says GLM-5.1 can run autonomously on a single task for up to eight hours, planning, executing, and revising as it goes. Strong on coding, office documents, and creative writing. Text only, with no image input, and a context window smaller than the largest frontier models. Open weights under an MIT licence.

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.