Feature Management

What is Percentage Rollout?

Q: What is Percentage Rollout?

A feature flag targeting strategy that enables a feature for a specific percentage of users.

A percentage rollout is a feature flag evaluation strategy where the flag returns true for a defined percentage of users. At 10%, roughly 1 in 10 users will see the feature; at 50%, roughly half will.

The percentage is typically evaluated deterministically using a hash of the user's ID and the flag key. This ensures that the same user consistently sees the same variant (no flickering), and that increasing the percentage from 10% to 20% adds new users without removing anyone who already had access.

Percentage rollouts are the core mechanism behind gradual rollouts and are often combined with other targeting rules — for example, "50% of users in the US" or "20% of users on the Pro plan."

Example

You set a feature flag to 30%, meaning about 30% of your users will see the new onboarding flow. User with ID user_123 is hashed and falls in the 22nd percentile — they see the new flow. User user_456 hashes to the 67th percentile — they see the old flow.

Related Terms

Gradual Rollout

A release strategy where a feature is incrementally released to larger percentages of users over time.

Feature Flag

A toggle that enables or disables a feature in your application without deploying new code.

User Targeting

The ability to enable or disable features for specific users based on their attributes or segments.

A/B Testing

An experiment that compares two or more variants of a page or feature to determine which performs better.

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