Feature flags

Feature flag services let you release, target and roll back features without a deploy. They differ less in the flags themselves than in what they bundle (experiments, analytics, approvals) and in how they bill: by monthly active users and server connections, by analytics events, or by flat plans sized by downloads.

We compare them on the same six indicators, read from each vendor's pricing, security and documentation pages:

• Pricing clarity: how many billing units you must estimate, and whether the pages leave prices out or contradict themselves.
• Free tier: whether a permanent free plan exists, its seats and flag limits, and whether it covers our reference scenario.
• Price for 50,000 monthly users: the lowest listed monthly cost for a team of 10 with one web app of 50,000 monthly active users, one backend service, 2 environments and 30 flags, with the assumption named where the page cannot settle it.
• Experimentation and rollout safety: built-in A/B testing, CUPED or sequential testing, and metric monitoring of rollouts.
• Compliance and data residency: the vendor's own SOC 2 Type II report, ISO 27001, a HIPAA BAA, an EU data region.
• Team and control: SAML SSO, an audit log, seat pricing, open-source SDKs, OpenFeature support and a self-hosted option.

Because the billing models differ, prices are compared at one reference scenario and the arithmetic is shown. Each review says which pages it was written from and when. Where we have run a product hands-on, the evidence is on its page.