compare
Fluent Bit vs Fluentd
The same facts for both, read from GitHub every night, and the relation a person reviewed.
| Fact | Fluent Bit | Fluentd |
|---|---|---|
| Language | C | Ruby |
| Licence | Apache-2.0 | Apache-2.0 |
| Stars | 8.1k | 14k |
| Latest | v5.1.3 | v1.19.4 |
| Last push | 2026-10-06 | 2026-10-06 |
| Release cadence | about 15 days between releases | about 83 days between releases |
| Active contributors | 30+ commit authors on the default branch in the last 90 days | 13 commit authors on the default branch in the last 90 days |
| Flags | none | none |
How they relate
Fluent Bit replaces Fluentd. Alternatives to Fluentd →
Full replacementFrom the same project, written in C with a much smaller footprint.
Published benchmarks, each linked to its source. The numbers depend on the hardware and the workload they were measured on.
CPU and memory of the CloudWatch output plugins on c5.9xlarge
10,000 log lines/s: Fluent Bit 0.19 vCPU and 65 MB, Fluentd 1.03 vCPU and 376 MB. Run by AWS.
Maximum Kubernetes log throughput with 100 pods
Fluent Bit 4.2.3 31,300 logs/s, Fluentd 1.19.1 5,100 logs/s (vlagent 143,000). Run by VictoriaMetrics.
Fluent Bit
Fluent Bit
unsigned The latest release, v5.1.3, carries no signature GitHub could verify.
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Fluentd
unsigned The latest release, v1.19.4, carries no signature GitHub could verify.
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