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Logging · head to head

Checkly vs Fluentd

Checkly logo

Checkly

Logging

Active reliability platform combining uptime monitoring, API testing, and incident response

From
Free
Rated
-
Full reviewWebsite
Fluentd logo

Fluentd

Logging

Open Source Data Collector for Unified Logging

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Checkly free tier has limited check allocations per month; Fluentd fluentd needs more than 60 MB of memory at runtime, against roughly 450 KB for Fluent Bit
  • They diverge on capability: Checkly covers Uptime monitoring, Fluentd covers Log collection.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Checkly and Fluentd actually diverge.

Attributes where Checkly and Fluentd differ
AttributeChecklyFluentd
Pricing modelsubscriptionopen-source
PlatformsWeb, CLI, APIWeb, Api
FoundedUnknown2011

Identical on both: starting price (Free), free tier (Yes), 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 Checkly

  • Uptime monitoring
  • Synthetic browser testing
  • API monitoring
  • Heartbeat monitoring
  • Monitoring-as-Code
  • Status pages
  • Root cause analysis
  • Global locations

Only in Fluentd

  • Log collection
  • Data parsing
  • Filtering and buffering
  • Event routing
  • API
  • Webhooks
  • REST
  • Web support

What people use each for

The jobs each tool is most often brought in to do.

Checkly

  • Monitor API endpoints with custom assertionsnot Fluentd
  • Test user journeys with browser automationnot Fluentd
  • Detect performance degradation across regionsnot Fluentd
  • Verify DNS and TCP connectivitynot Fluentd
  • Ensure cron jobs and background tasks completenot Fluentd

Fluentd

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

Where each one falls short

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

Checkly

  • Free tier has limited check allocations per month
  • Overage charges can add up with high-volume workloads
  • Status pages require separate paid tier
  • Root cause analysis is separate billing component

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

Pricing, plan by plan

Checkly

Free
  • HobbyFree
    • 10 uptime monitors
    • 1,000 browser checks monthly
    • 10,000 API checks monthly
  • Team$64/month
    • 75 uptime monitors
    • 12,000 browser checks monthly
    • 100,000 API checks monthly
  • Enterprise$undefined/custom
    • Custom monitor quantities
    • All 22 global locations
    • 1-second check frequency

Fluentd

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

Which should you pick?

Choose Checkly if

  • You need uptime monitoring.
  • You want to start without paying.
  • You work on Web, CLI, API.
  • You also want synthetic browser testing.
Checkly review

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

Questions people ask

Is Checkly or Fluentd better?
Neither clearly leads. Checkly starts at Free and Fluentd at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Checkly or Fluentd?
Checkly starts at Free and Fluentd at Free.
Does Checkly or Fluentd run on more platforms?
Checkly runs on Web, CLI, API. Fluentd runs on Web, Api.
Can I use Checkly for free?
Both have a free tier, so you can try either at no cost before committing.
What is Checkly best used for?
Checkly is most often used for monitor api endpoints with custom assertions, test user journeys with browser automation, detect performance degradation across regions, verify dns and tcp connectivity. Of those, monitor api endpoints with custom assertions and test user journeys with browser automation are not what Fluentd is typically brought in for.
What can Checkly do that Fluentd cannot?
Checkly covers Uptime monitoring, Synthetic browser testing, API monitoring, Heartbeat monitoring. Fluentd covers Log collection, Data parsing, Filtering and buffering, Event routing.

Answered from the vendors’ own pages

Checkly: What is included in the free Checkly plan?

The free Hobby plan includes 10 uptime monitors, 1,000 monthly browser checks, 10,000 monthly API checks, 6 monitoring locations, and 2-minute minimum check frequency with email, Slack, and webhook alerts.

Source
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
Checkly: Can I write monitoring checks in my preferred language?

Yes, Checkly uses TypeScript/JavaScript for monitoring-as-code, integrated with Playwright for browser testing and supporting REST API testing.

Source
Checkly: How much does status page add to my bill?

Status pages cost between $0-$30/month depending on your plan tier, billed separately from core monitoring.

Source
Checkly: What is the minimum check frequency?

The Hobby and Starter plans support 2-minute and 1-minute minimums respectively. The Team plan supports 30-second intervals, while Enterprise offers 1-second minimum frequency.

Source
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