Long task - MDN Web Docs Glossary: Definitions of Web-related terms 编辑

A long task  is a task that takes more than 50ms to complete. It is an uninterrupted period where the main UI thread is busy for 50 ms or longer. Common examples include long running event handlers, expensive reflows and other re-renders, and work the browser does between different turns of the event loop that exceeds 50 ms.

See also

• Long task API