Software · head to head
Loki vs Fluent Bit
The short version
- Each has a real cost: Loki the Grafana Cloud free tier caps log ingestion at 50 GB a month with 14 day retention; Fluent Bit fluent Bit ships over 100 built in plugins against more than 1,000 external plugins available for Fluentd, so fewer integrations exist out of the box
- They diverge on capability: Loki covers Log aggregation, Fluent Bit covers Log collection.
Where they differ
Only the attributes on which Loki and Fluent Bit actually diverge.
| Attribute | Loki | Fluent Bit |
|---|---|---|
| Founded | 2014 | 2015 |
Identical on both: starting price (Free), pricing model (open-source), free tier (Yes), platforms (Web, Api), user rating (Not yet rated), category (Unknown).
What each one covers
Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.
Only in Loki
- Log aggregation
- Label-based indexing
- Real-time log streaming
- LogQL query language
Only in Fluent Bit
- Log collection
- Lightweight processing
- Data parsing
- Event filtering
Both cover
- API
- Webhooks
- REST
- Web support
- Api support
What people use each for
The jobs each tool is most often brought in to do.
Loki
- Aggregating application and infrastructure logs with label based indexingnot Fluent Bit
- Querying logs alongside metrics in Grafananot Fluent Bit
Fluent Bit
- Lightweight log and metric forwarding from containers and edge devicesnot Loki
- Kubernetes node level log collection with a small memory footprintnot Loki
- Filtering and enriching telemetry before shipping it to a backendnot Loki
Where each one falls short
Documented limitations, not opinions. Every one is a constraint you would hit in normal use.
Loki
- The Grafana Cloud free tier caps log ingestion at 50 GB a month with 14 day retention
- Paid log pricing is split across three separate meters, at $0.050 per GB processed, $0.400 per GB written and $0.100 per GB retained
- Retaining logs is billed separately from ingesting them, so keeping data costs on an ongoing basis rather than once
- The Pro plan carries a $19 a month platform fee before any usage charges
Fluent Bit
- Fluent Bit ships over 100 built in plugins against more than 1,000 external plugins available for Fluentd, so fewer integrations exist out of the box
- It is written in C, so extending it beyond the built in plugins means writing C rather than Ruby
- Dependencies are zero only until a plugin requires one
Pricing, plan by plan
Loki
Free- FreeFree
- Log aggregation
- Label-based indexing
- Real-time log streaming
Fluent Bit
Free- FreeFree
- Log collection
- Lightweight processing
- Data parsing
Which should you pick?
Choose Loki if
- You need log aggregation.
- You want to start without paying.
- You work on Web, Api.
- You also want label-based indexing.
Choose Fluent Bit if
- You need log collection.
- You want to start without paying.
- You work on Web, Api.
- You also want lightweight processing.
Questions people ask
- Is Loki or Fluent Bit better?
- Neither clearly leads. Loki starts at Free and Fluent Bit at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
- Which is cheaper, Loki or Fluent Bit?
- Loki starts at Free and Fluent Bit at Free.
- Does Loki or Fluent Bit run on more platforms?
- Both run on Web, Api, so platform support will not decide this one for you.
- Can I use Loki for free?
- Both have a free tier, so you can try either at no cost before committing.
- What is Loki best used for?
- Loki is most often used for aggregating application and infrastructure logs with label based indexing, querying logs alongside metrics in grafana. Of those, aggregating application and infrastructure logs with label based indexing and querying logs alongside metrics in grafana are not what Fluent Bit is typically brought in for.
- What can Loki do that Fluent Bit cannot?
- Loki covers Log aggregation, Label-based indexing, Real-time log streaming, LogQL query language. Fluent Bit covers Log collection, Lightweight processing, Data parsing, Event filtering. Both handle API, Webhooks, REST, Web support.