Feature flag
Turning a feature on or off from configuration, without a new release, so finished code can wait, be tried on a few users or be switched back safely.
Updated October 2026 · with examples from our own builds
What does feature flag mean in practice?
Feature flags separate shipping code from switching it on. A payout automation can ship turned off; a paid plan can wait for live keys; a behaviour can differ for some users. Flipping the flag changes behaviour straight away, with no app store review or deploy.
They lower launch risk and keep commercial choices reversible, such as whether Premium removes ads. They also let a team merge work early instead of holding it on a branch.
Flags need housekeeping. Each should have an owner and a reason, high-impact switches deserve the protection of any privileged action, and old flags should go once the decision is settled.
Feature flag at a glance
- Lets you
- Ship code switched off and turn it on later
- Protect
- High-impact switches like other privileged actions
- Clean up
- Flags whose decision is settled
Where has feature flag come up in our builds?
Whether Premium removes ads is one setting, PREMIUM_IS_AD_FREE, which governs the feed, the ads bootstrap and the ad-preferences row in Settings. In July 2026 the client chose to show ads to Premium members too, so it is off, and one change restores ad-free Premium.
The admin console manages feature flags, and kill switches need a fresh 2FA code tied to the same person and session.
Money features stay closed in each country until its Market record switches them on, and the dispatch timers run behind a superadmin switch that pauses them.
Common questions about feature flag
Can a feature flag change a mobile app without an app store update?
Yes, if the app reads the flag from the server at runtime. The code for both behaviours has to be in the released app already; the flag only chooses between them.
Who should be allowed to flip feature flags?
A small set of roles, with every change logged. Flags that affect money or every user deserve the same protection as other privileged actions, such as a fresh 2FA code.
Related terms
Sources
Planning a product and not sure where feature flag fits? Ask us, or browse all 116 terms in the glossary.