Ship code. Control rollout.
No redeploy required.
Wrap any code path in a flag and control it from the dashboard. Toggle from the dashboard, no deployment needed.
How it works
Create a flag
Name your flag and set a default value — what the SDK returns when no targeting rules match.
Add targeting rules
Define who sees which value. Target by segment, user attribute, or roll out to a percentage. Rules evaluate in order.
Ship and toggle
Deploy your code with the flag check in place. Enable, disable, or adjust rollout percentage from the dashboard — no redeploy. Changes reach your SDKs within about a minute.
Flag type
Boolean
The standard on/off flag. Returns true or false.
Use for feature gates, kill switches, and targeted rollouts.
Simple check
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With context
key: 'user-123',
plan: 'pro',
country: 'DE',
});
Key capabilities
Client-side evaluation
The SDK downloads your flag rules and evaluates them locally. No network request on every flag check — evaluation is a fast in-memory lookup.
Toggle without a deploy
Enable or disable a flag from the dashboard with no code change. SDK instances pick up the change on their next background refresh — within about a minute. No deployment, no cache flush needed.
Default values
Every flag has a default that's returned when no targeting rule matches, or when the SDK can't reach Flaggy. Your code always gets a value.
Environment isolation
Flags are configured per environment. A flag can be enabled in staging and disabled in production — rules and values are independent per environment.
Percentage rollout
Roll out to 5% of users, check your metrics, then increase to 25%, 50%, 100%. Bucketing is deterministic — a user always gets the same result once assigned.
Start shipping behind flags
Free plan available. No credit card required.