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
From $45 per month (indicative, Start-up plan)
Free tierQuote on request
Quote onlyWhat drives the bill
The metric that actually scales your invoice.
Considerably cheaper than LaunchDarkly, and self-hosting removes usage pricing entirely.
Enterprise annual contracts, commonly in the tens of thousands and up. Priced by traffic and modules.
Free tier
Free cloud tier with a monthly request allowance; open-source self-hosting is unlimited.
No free tier.
Open source
BSD-3-Clause (core)
Self-hostable
No-code authoring
Languages
Platforms
Fits teams
Adoption
Established
Flagsmith · since 2018
Widely used
Optimizely · since 2010
Strengths
Limitations
Best for
Teams wanting straightforward flags without LaunchDarkly pricing or Unleash's operational depth.
Large marketing organisations running continuous experimentation on high-traffic sites.
All of these integrate with: Segment, Slack.
Pricing last reviewed August 2026 and is indicative only — confirm on each vendor’s own page.