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Logging · head to head

Checkly vs Flagsmith

Checkly logo

Checkly

Logging

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

From
Free
Rated
-
Full reviewWebsite
Flagsmith logo

Flagsmith

Software Development

Open-source feature flag and remote config platform

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Checkly free tier has limited check allocations per month; Flagsmith the Free plan supports only a single team member, limiting collaboration for small teams.
  • They diverge on capability: Checkly covers Uptime monitoring, Flagsmith covers Feature flags.

Where they differ

Only the attributes on which Checkly and Flagsmith actually diverge.

Attributes where Checkly and Flagsmith differ
AttributeChecklyFlagsmith
Pricing modelsubscriptionfreemium
PlatformsWeb, CLI, APIweb, api
CategoryLoggingSoftware Development

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated).

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 Flagsmith

  • Feature flags
  • Segments
  • A/B testing
  • Scheduled flags
  • SDKs
  • SAML/SSO

What people use each for

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

Checkly

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

Flagsmith

  • Gradual feature rollouts across environmentsnot Checkly
  • Remote configuration without redeploying codenot Checkly
  • Running A/B tests tied to feature flagsnot Checkly
  • Self-hosting feature flags for data residency requirementsnot 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

Flagsmith

  • The Free plan supports only a single team member, limiting collaboration for small teams.
  • Exceeding request limits triggers overage charges after a one-time 30-day grace period.
  • Enterprise-grade SSO and governance are locked behind the Scale-Up and Enterprise tiers.
  • Self-hosting requires operating and updating the platform yourself, unlike a fully managed SaaS competitor.

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

Flagsmith

Free
  • FreeFree
    • Up to 50,000 requests/month
    • 1 team member
    • Unlimited feature flags, environments, identities and segments
  • Start-Up$45/month
    • Up to 1,000,000 requests/month
    • 3 team members
    • Scheduled flags, 2FA, A/B testing, integrations, email support
  • Scale-Up$300/month
    • 5,000,000+ requests/month
    • 5-20 team members
    • SAML/SSO, governance features, priority support

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 Flagsmith if

  • You need feature flags.
  • You want to start without paying.
  • You work on web, api.
  • You also want segments.
Flagsmith review

Questions people ask

Is Checkly or Flagsmith better?
Neither clearly leads. Checkly starts at Free and Flagsmith at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Checkly or Flagsmith?
Checkly starts at Free and Flagsmith at Free.
Does Checkly or Flagsmith run on more platforms?
Checkly runs on Web, CLI, API. Flagsmith 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 Flagsmith is typically brought in for.
What can Checkly do that Flagsmith cannot?
Checkly covers Uptime monitoring, Synthetic browser testing, API monitoring, Heartbeat monitoring. Flagsmith covers Feature flags, Segments, A/B testing, Scheduled flags.

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
Flagsmith: What does Flagsmith cost?

Flagsmith has a Free plan, a Start-Up plan from $40-45/month, a Scale-Up plan from $250-300/month, and custom Enterprise pricing.

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
Flagsmith: Is there a free plan, and what are its limits?

The Free plan supports up to 50,000 requests per month and 1 team member, with unlimited feature flags, environments, identities and segments.

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
Flagsmith: How is usage metered?

Usage is metered by monthly API requests; exceeding a plan's limit triggers overage charges starting around $50 per million requests, with a 30-day grace period the first time a paid plan exceeds its limit.

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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