Log Processor & Forwarder

Collect > Parse > Filter > Deliver

Fluent Bit v1.8.12 is out!

It has been released on Jan 24, 2021, check out the Release Notes, read the Updated Documentation or jump directly to the Downloads Section.

Fluent Bit is an open source Log Processor and Forwarder which allows you to collect any data like metrics and logs from different sources, enrich them with filters and send them to multiple destinations. It's the preferred choice for containerized environments like Kubernetes.

Fluent Bit is designed with performance in mind: high throughput with low CPU and Memory usage. It's written in C language and has a pluggable architecture supporting more than 70 extensions for inputs, filters and outputs.

Fluent Bit is a CNCF (Cloud Native Computing Foundation) subproject under the umbrella of Fluentd.

We are part of a wide community, no vendor lock-in.



It has been designed as a lightweight solution with high performance in mind. From a design perspective, it's fully asynchronous (event-driven) and take the most of the operating systems API for performance and reliability.


All inputs, filters and outputs features are implemented through the plugins interface. Extend the features with C, Lua (filters) or Golang (outputs).


Measuring is important. Fluent Bit comes with native plugins to gather metrics from your CPU, Memory, Disk I/O and Network usage on Linux systems. In addition, it can receive metrics from external services like Statsd and Collectd.


Event Driven

Fluent Bit as a service is fully event-driven, it only use asynchronous operations to collect and deliver data.

Flexible Routing

The data that comes in the pipeline, can be routed to multiple places using custom routing rules. Ship your data to multiple places with zero-copy strategy.


It configuration is very simple and human-readable, it allow to specify how it will behave, which features to enable and how Routing is performed. Optionally Fluent Bit can run from the command line without it.

I/O Handler

The Input/Output layer provides an abstraction that allow to perform read/write operations in an asynchronous way.

Upstream Manager

When dealing with upstream backends like remote network services, handling TCP connections can be challenging. The Upstream manager simplify the connection process and take care of timeout/network exceptions and Keepalive states.

Security & TLS

When delivering data to destinations, output connectors inherit full TLS capabilities in an abstracted way. Add your certificates as required.