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Logging · head to head

Fluentd vs Rollbar

Fluentd logo

Fluentd

Logging

Open Source Data Collector for Unified Logging

From
Free
Rated
-
Full reviewWebsite
Rollbar logo

Rollbar

Logging

Real-Time Error Tracking and Debugging

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Fluentd fluentd needs more than 60 MB of memory at runtime, against roughly 450 KB for Fluent Bit; Rollbar the free plan allows 5,000 occurrences a month with 30 day retention
  • They diverge on capability: Fluentd covers Log collection, Rollbar covers Error tracking.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Fluentd and Rollbar actually diverge.

Attributes where Fluentd and Rollbar differ
AttributeFluentdRollbar
Pricing modelopen-sourcefreemium
Founded20112012

Identical on both: starting price (Free), free tier (Yes), platforms (Web, Api), user rating (Not yet rated), category (Logging).

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 Fluentd

  • Log collection
  • Data parsing
  • Filtering and buffering
  • Event routing

Only in Rollbar

  • Error tracking
  • Real-time alerts
  • Error grouping
  • Source maps

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.

Fluentd

  • Unified log collection and routing from many sources to many destinationsnot Rollbar
  • Parsing and transforming log records before forwardingnot Rollbar
  • Aggregating logs from containers into Elasticsearch, S3 or a SIEMnot Rollbar

Rollbar

  • Tracking application errors and exceptions across deploymentsnot Fluentd
  • Grouping and alerting on production error occurrencesnot Fluentd

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Fluentd

  • Fluentd needs more than 60 MB of memory at runtime, against roughly 450 KB for Fluent Bit
  • Fluentd is built as a Ruby gem and depends on other gems, so a Ruby runtime is required
  • Its capability comes from over 1,000 external plugins rather than built in functionality, so each added input or output is a separate dependency
  • The Fluent Bit documentation states that cloud providers have switched from Fluentd to Fluent Bit for performance and compatibility and calls Fluent Bit the next generation solution

Rollbar

  • The free plan allows 5,000 occurrences a month with 30 day retention
  • Retention is a paid ladder rather than a setting, at up to 90 days on Essentials and up to 180 on Advanced
  • Advanced alerting, the RQL analytics query language and SCIM provisioning are excluded from the free plan
  • Enterprise requires a $4M annual plan minimum
  • No price is published for Essentials or Advanced, so only the free tier has a visible cost

Pricing, plan by plan

Fluentd

Free
  • FreeFree
    • Log collection
    • Data parsing
    • Filtering and buffering

Rollbar

Free
  • FreeFree
    • 5K occurrences per month
    • 1K replays
    • Real-time alerts
  • Essentials$null/month
    • 10K-50M occurrences
    • 4K credits included
    • 90-day retention
  • Advanced$null/month
    • 8K credits
    • Adaptive alerts
    • RQL and Metrics API
  • Enterprise$null/month
    • 80M+ events
    • Direct Slack support
    • Priority SLAs

Which should you pick?

Choose Fluentd if

  • You need log collection.
  • You want to start without paying.
  • You work on Web, Api.
  • You also want data parsing.
Fluentd review

Choose Rollbar if

  • You need error tracking.
  • You want to start without paying.
  • You work on Web, Api.
  • You also want real-time alerts.
Rollbar review

Questions people ask

Is Fluentd or Rollbar better?
Neither clearly leads. Fluentd starts at Free and Rollbar at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Fluentd or Rollbar?
Fluentd starts at Free and Rollbar at Free.
Does Fluentd or Rollbar run on more platforms?
Both run on Web, Api, so platform support will not decide this one for you.
Can I use Fluentd for free?
Both have a free tier, so you can try either at no cost before committing.
What is Fluentd best used for?
Fluentd is most often used for unified log collection and routing from many sources to many destinations, parsing and transforming log records before forwarding, aggregating logs from containers into elasticsearch, s3 or a siem. Of those, unified log collection and routing from many sources to many destinations and parsing and transforming log records before forwarding are not what Rollbar is typically brought in for.
What can Fluentd do that Rollbar cannot?
Fluentd covers Log collection, Data parsing, Filtering and buffering, Event routing. Rollbar covers Error tracking, Real-time alerts, Error grouping, Source maps. Both handle API, Webhooks, REST, Web support.

Answered from the vendors’ own pages

Fluentd: How much does Fluentd cost?

Fluentd is free and open-source under the Apache 2 License from the Cloud Native Computing Foundation (CNCF). There are no subscription fees, licensing costs, or commercial pricing tiers.

Source
Rollbar: How much does Rollbar cost?

Free plan is $0 with 5K occurrences per month. Essentials, Advanced, and Enterprise plans do not have published pricing and require contact with sales.

Source
Rollbar: Is there a free trial?

Yes, a 14-day full access trial is available with 200K occurrences, 10K replays, and 15K credits.

Source
Rollbar: How are overages handled?

Three overage protection options are available: stop processing at plan limits, enable on-demand billing at standard rates, or set a custom overage budget cap.

Source
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