FAQ

SDKs and APIs

How does bucketing in the Statsig SDKs work?

Can I add a layer to a running experiment?

No. Layers are fixed after an experiment starts to preserve the integrity of results. Statsig may support editing layers in the future.

Can I rename an existing experiment or feature gate?

Yes. When renaming an entity (for example, a feature gate, experiment, or layer), only its display name changes. The underlying ID referenced in your code remains unchanged because IDs are immutable, which prevents breaking existing implementations.

Why define parameters instead of reading the experiment group?

Parameters let you iterate quickly without code changes and support richer experiment setups. For example:

// Group-based approach — requires code changes for each variant
if (otherEngine.getExperiment('button_color_test').getGroup() === 'Control') {
  color = 'BLACK';
} else if (otherEngine.getExperiment('button_color_test').getGroup() === 'Blue') {
  color = 'BLUE';
}

// Statsig parameter approach — variants can be changed from the console
const color = statsig.getExperiment('button_color_test').getString('button_color', 'BLACK');

Why aren't exposures or custom events showing up?

My SDK language isn't listed. Can I still use Statsig?

How do I retrieve all exposures for a user?

const assignments = statsig.getClientInitializeResponse(user, 'client-key', { hash: 'none' });

What happens if I check a config that doesn't exist?

Feature gates

If I change the rollout percentage, do existing users keep their result?

Yes. Increasing the pass percentage (for example, 10% to 20%) keeps the original 10% and adds new traffic until the new percentage is reached. Decreasing it removes the newest slice first. To reshuffle all users, you must resalt the gate. Experiments behave differently; use targeting gates for deterministic control.

Statistics

What statistical tests does Statsig use?

How does Statsig handle low sample sizes?

When should I use one-sided vs. two-sided tests?

Use one-sided when you only care about movement in a single direction; it increases power but hides movement in the opposite direction.

Experimentation

How do I get started with an A/B test?

Can I target experiments to specific users (e.g., iOS only)?

Yes. Use a feature gate with targeting rules as a pre-filter for your experiment.

Billing

What counts as a billable event?

Any gate/experiment check or event logged through the SDK or APIs. Pre-computed metrics and custom metrics based on existing data also count.

How do I monitor and manage billable volume?

1. Export usage from the Usage and Billing tab.
2. Pivot by event to identify heavy hitters.
3. Admins receive alerts at 50/75/100% of contract.

How many projects can I create with a Pro subscription?

Platform usability

When should I create a new project?

Projects have distinct boundaries. If you're using the same userIDs and metrics across surfaces, apps or environments, put them in the same project. Create a new project when you're managing a separate product with unique user IDs and metrics.

For example, if you have a marketing website (anonymous users) and a product (signed-in users), you may want to separate them. However, if you want to track success across both you should manage them in the same project (for example, from user signup on the marketing website to user engagement within the product).

Reasons to avoid creating a new project:

• Segregating by environment: Statsig supports environments natively, and you can customize them. You can turn features or experiments on and off by environment.
• Segregating by platform: If you have an iOS app and a web app, collecting data in the same project lets you view data by platform and understand whether you increased the overall metric or moved users from one platform to the other.

How can I monitor the health of Statsig and get support?