Microsoft Webwright is a simple SWE-style browser agent framework that achieves state-of-the-art results on long-horizon web tasks. It gives agents a terminal that allows them to launch multiple browser sessions to inspect pages and complete web tasks. Webwright captures and inspects screenshots only when needed, and it enforces each web task to be completed end-to-end within a re-runnable Python script. It uses a small harness that adds just enough structure around completion, context, and reuse to avoid creating new failure modes.