How to use feature flags in JavaScript and TypeScript

📰 Dev.to · Flaggy

Learn to implement feature flags in JavaScript and TypeScript to control and test new features

intermediate Published 20 May 2026

Action Steps

Implement feature flags using a library like Flaggy in your JavaScript or TypeScript project
Create a feature flag to toggle a new feature on or off
Use a configuration file to manage feature flags
Write conditional code to check the state of a feature flag
Test and refine your feature flags using A/B testing or canary releases

Who Needs to Know This

Developers and product managers can benefit from using feature flags to test and refine new features before releasing them to the public

Key Insight

💡 Feature flags allow you to decouple feature rollout from code deployment, giving you more control over the release process

Key Takeaways

Learn to implement feature flags in JavaScript and TypeScript to control and test new features

A practical guide to implementing feature flags in JS/TS: what they are, when to use them, and how to...