A. GPT-5.4
B. Claude 4
C. Gemini 2.5
D. Llama 4
Early in March 2026, Anthropic released Claude 4 (more precisely, Claude Opus 4), a new “Reasoning Engine” with extended thinking capabilities for intricate software coding and agentic workflows. For several hours, the model can reason continuously, switching between in-depth examination and the use of tools like web searches.
The “extended thinking with tool use” feature of the reasoning engine allows Claude to reason step-by-step, pause to access files or search the web, and then continue reasoning for lengthy, intricate coding projects.
The hybrid architecture provides developers with flexibility dependent on task difficulty by offering both deep, protracted thinking modes and quick, almost instantaneous replies.
With its enormous 2-million token context window, it can process whole codebases or lengthy documentation simultaneously.