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Logging · head to head

Fluentd vs Sematext

Fluentd logo

Fluentd

Logging

Open Source Data Collector for Unified Logging

From
Free
Rated
-
Full reviewWebsite
Sematext logo

Sematext

Logging

Full Stack Observability Platform

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; Sematext the $5 Basic plan caps ingestion at 500 MB a day and retains logs for 7 days
  • They diverge on capability: Fluentd covers Log collection, Sematext covers Log aggregation.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Fluentd and Sematext actually diverge.

Attributes where Fluentd and Sematext differ
AttributeFluentdSematext
Pricing modelopen-sourceusage-based
Founded20112007

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 Sematext

  • Log aggregation
  • APM
  • Metrics monitoring
  • Anomaly detection

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 Sematext
  • Parsing and transforming log records before forwardingnot Sematext
  • Aggregating logs from containers into Elasticsearch, S3 or a SIEMnot Sematext

Sematext

  • Centralised log management and search across servicesnot Fluentd
  • Infrastructure and application monitoring alongside logsnot 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

Sematext

  • The $5 Basic plan caps ingestion at 500 MB a day and retains logs for 7 days
  • Ingestion and storage are billed on separate meters, at $0.10 per GB received and $0.15 per GB stored
  • Retention is a plan property rather than a setting, so keeping logs longer means moving tier
  • The published pricing page renders Standard and Pro figures from unresolved template placeholders, so only the Basic numbers are actually readable

Pricing, plan by plan

Fluentd

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

Sematext

Free
  • FreeFree
    • Log aggregation
    • APM
    • Metrics monitoring

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 Sematext if

  • You need log aggregation.
  • You want to start without paying.
  • You work on Web, Api.
  • You also want apm.
Sematext review

Questions people ask

Is Fluentd or Sematext better?
Neither clearly leads. Fluentd starts at Free and Sematext at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Fluentd or Sematext?
Fluentd starts at Free and Sematext at Free.
Does Fluentd or Sematext 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 Sematext is typically brought in for.
What can Fluentd do that Sematext cannot?
Fluentd covers Log collection, Data parsing, Filtering and buffering, Event routing. Sematext covers Log aggregation, APM, Metrics monitoring, Anomaly detection. 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
Sematext: How much does Sematext cost?

Sematext uses a transparent usage-based pricing model. Customers can set a Max Daily Volume for automatic rejection of excess data to prevent unexpected charges and keep costs predictable. Specific tier pricing is available through their cost calculator tool.

Source
Sematext: How does Sematext's pricing compare to competitors?

Sematext is positioned as +3x cheaper than Datadog, with potential annual savings of $800,000 for customers logging more than 200TB/month and a reported 75% decrease in price per GB compared to alternatives.

Source
Sematext: Does Sematext offer a free trial?

Yes, Sematext offers a 14-day free trial with no credit card required, allowing you to test the platform before committing to a paid plan.

Source
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