Feature flags let you deploy code to production without making it visible to all users immediately. You can enable features for specific users, gradually roll out changes, and quickly disable problematic features without deploying new code. For WordPress plugin developers, feature flags provide a safety net for continuous deployment.
This guide covers how to implement feature flags in WordPress plugins.
Simple Database Flags
The simplest feature flag implementation stores flag values in the WordPress options table. Use update_option() to set a flag and get_option() to check its value. Create an admin settings page where flags can be toggled. This approach works well for plugins with a small number of flags. Each flag is a boolean value that controls whether a feature is visible.
Use descriptive flag names like ‘myplugin_feature_new_checkout’ to make the purpose clear.
User-Specific Flags
For gradual rollouts, enable features for specific users. Store feature flags in user meta with update_user_meta() and check them with get_user_meta(). Roll out features to beta testers first, then staff, then a percentage of users. User-specific flags let you test with real users before full release.
Use a user role or capability check to determine which users see new features. Create a beta tester role or assign a custom capability.
Percentage Rollouts
Roll out features to a percentage of users using a hash of the user ID. Calculate a hash of the user ID and compare it to the rollout percentage. Users with hash values below the threshold see the new feature. This provides a consistent experience — users don’t see the feature toggle on and off between requests.
Increase the rollout percentage gradually — 1%, 5%, 25%, 50%, 100% — monitoring for issues at each step.
Feature Flag Service
For advanced feature flag management, use a dedicated feature flag service. LaunchDarkly, Unleash, or Split provide feature flag management with targeting, gradual rollouts, and kill switches. These services integrate with WordPress via HTTP API calls. They provide a dashboard for managing flags without deploying code changes.
Feature flag services are ideal for plugin businesses with multiple developers and frequent deployments.
Cleaning Up Flags
Remove feature flags once features are fully released. Stale flags accumulate and complicate code. After a feature has been rolled out to 100% and confirmed stable, remove the flag condition and the flag’s user meta or option. Keep deprecated flags temporarily for backward compatibility during the transition period.
Document flag removal as part of your release process.
Il punto fondamentale
Feature flags enable safe, continuous deployment for WordPress plugins. Start with simple database flags, use user-specific flags for targeted rollouts, implement percentage rollouts for gradual releases, and clean up flags after full release. Feature flags reduce deployment risk and enable faster iteration.
