Claude Opus 5 at Max effort leads Fullstack Code Arena with 1,699 points.
Significantly ahead of Kimi K3 Max
Fullstack Code Arena asks models to build working web apps through multi-step planning and tools, instead of answering isolated coding questions.
Models can create and edit files, run commands, use databases, authentication and external APIs, then produce a live application for testing.
Its specialty is testing models inside a complete tool-using build process and judging the finished app, which better resembles how coding agents work.