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testcritic

Optimizely vs Flagsmith

Feature checklists rarely decide anything. What decides it is the pricing metric, who has to write the tests, and which limitation you can live with.

Entry price

Quote on request

Quote only

From $40 per month (Start-Up, billed yearly; $45 monthly)

Free tier

What drives the bill

The metric that actually scales your invoice.

Enterprise annual contracts, commonly in the tens of thousands and up. Priced by traffic and modules.

Free covers 50k requests a month and one seat; Start-Up raises that to 1M requests and 3 seats, Scale-Up is $250/month yearly. Considerably cheaper than LaunchDarkly, and self-hosting removes usage pricing entirely.

Free tier

No free tier.

Free cloud tier with a monthly request allowance; open-source self-hosting is unlimited.

Open source

BSD-3-Clause (core)

Self-hostable

No-code authoring

Languages

JavaScriptPythonJavaC#GoRubyPHPCodeless
JavaScriptTypeScriptPythonJavaC#GoRubyPHPSwiftKotlin

Platforms

WebAPIiOSAndroid
WebAPIiOSAndroid

Fits teams

Enterprise
Solo / side projectStartupScale-up / mid-marketEnterprise

Adoption

Widely used

Optimizely · since 2010

Established

Flagsmith · since 2018

Strengths

  • The most capable visual editor for non-technical experiment authoring.
  • Deep personalisation and audience-targeting features.
  • Established statistics with sequential testing, so peeking is handled correctly.
  • Genuinely easy self-hosting with a Docker image and Helm chart.
  • Simple, comprehensible pricing.
  • Remote config alongside flags, which covers a lot of mobile use cases.

Limitations

  • Expensive, with a suite-oriented sales motion that pushes adjacent products.
  • Client-side testing causes flicker and is increasingly blocked by browsers and blockers.
  • Heavyweight for teams that only need a handful of experiments.
  • Experimentation features are basic.
  • Smaller company and community than the leaders.
  • Fewer governance controls for large organisations.

Best for

Large marketing organisations running continuous experimentation on high-traffic sites.

Teams wanting straightforward flags without LaunchDarkly pricing or Unleash's operational depth.

All of these integrate with: Segment, Slack.

Pricing last reviewed August 2026 and is indicative only — confirm on each vendor’s own page.