Fluentd
Fluentd is a free, open-source data collector for creating a unified logging layer.
What Fluentd is
Fluentd is a free, open-source data collector for creating a unified logging layer. It uses JSON to bring log collection, filtering, buffering and output together across different data sources and destinations. More than 500 community plugins connect it to inputs and outputs including Elasticsearch and Kibana, Splunk, AWS S3, Kafka, BigQuery, Datadog and OpenTelemetry.
Fluentd supports memory and file buffering, failover and high availability to help prevent data loss between nodes. The project reports that a vanilla instance uses 30–40 MB of memory and processes 13,000 events per second per core. Fluentd v1 is available for Linux, Mac OSX and Windows; community distributions also include Docker images, Kubernetes DaemonSet and Ruby gems. It is self-hosted and its components are available under the Apache 2 License. The project is a CNCF graduated project and lists both community help and commercial support. Its homepage identifies vulnerabilities patched in Fluentd v1.19.3 and advises updating fluent-package to v6.0.4.
Good
- More than 500 community plugins are available.
- Supports memory and file buffering, failover and high availability.
- Runs on Linux, Mac OSX and Windows.
- Free under the Apache 2 License.
Watch out
- Deployment is self-hosted.
- The project advises updating fluent-package to v6.0.4.
Who it suits
Fluentd suits teams that need to collect, filter, buffer and route logs across varied sources and destinations. It is aimed at users able to manage a self-hosted, open-source collector.
Verdict
Fluentd offers a flexible logging pipeline built around JSON and a large plugin ecosystem. Self-hosting teams should review the listed security update guidance.
Plans and prices
From Fluentd's own pricing page, checked 11 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Fluentd | Free | Open source data collector · Apache 2 License |
The facts
Each one read from Fluentd's own pages, with the date it was checked.
What it does
- Archive export
- Yeschecked 20 Sep 2026
- Audience and scale
- The project says 5,000+ data-driven companies rely on Fluentd and its largest user collects logs from 50,000+ servers.checked 11 Oct 2026
- Data processing
- Fluentd uses JSON to unify log collection, filtering, buffering, and output across sources and destinations.checked 11 Oct 2026
- Deployment options
- self-hostedchecked 20 Sep 2026
- History
- Fluentd was conceived in 2011 and open-sourced in October 2011.checked 11 Oct 2026
- Integrations
- Listed outputs include Elasticsearch and Kibana, Splunk, AWS S3, Kafka, BigQuery, Datadog, and OpenTelemetry.checked 11 Oct 2026
- License and governance
- Fluentd is a CNCF graduated project and its components are available under the Apache 2 License.checked 11 Oct 2026
- Live log tailing
- Yeschecked 20 Sep 2026
- Log pipelines
- Yeschecked 20 Sep 2026
- Plugins
- Fluentd has 500+ community plugins connecting dozens of data sources and outputs.checked 11 Oct 2026
- Purpose
- Fluentd is an open source data collector for a unified logging layer.checked 11 Oct 2026
- Reliability
- Fluentd supports memory and file buffering, failover, and high availability to help prevent inter-node data loss.checked 11 Oct 2026
- Resource use
- A vanilla Fluentd instance runs on 30–40 MB of memory and can process 13,000 events per second per core.checked 11 Oct 2026
- Security
- The Fluentd homepage says vulnerabilities CVE-2026-44024, CVE-2026-44025, CVE-2026-44160, and CVE-2026-44161 were patched in Fluentd v1.19.3 and advises updating fluent-package to v6.0.4.checked 11 Oct 2026
- Structured log parsing
- Yeschecked 20 Sep 2026
- Support
- The project lists community help and commercial support from companies offering Fluentd enterprise services.checked 11 Oct 2026
- Supported systems
- Fluentd v1 is available for Linux, Mac OSX, and Windows; community distributions also include Docker images, Kubernetes DaemonSet, and Ruby gems.checked 11 Oct 2026
The company
- Founded
- 2011checked 28 Sep 2026
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