overview
What is Celery?
Celery is an open-source distributed task queue system developed by the Celery Project that enables developers and engineers to process vast amounts of messages asynchronously or on a schedule. It is widely used in production systems, including by Instagram, to handle millions of tasks daily. Celery functions as a mechanism to distribute work across threads or machines, allowing developers to offload time-consuming tasks from the main application thread to background worker processes. This improves application responsiveness and user experience. Celery is based on distributed message passing and requires a message broker, such as RabbitMQ or Redis, to mediate between clients and workers, enabling high availability and horizontal scaling. Recent stable releases include Version 5.6.2 on March 26, 2026, and Version 5.6.0 on November 30, 2025, which dropped support for Python 3.8 and introduced initial support for Python 3.14.