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10 Types of Feature Flags you Should Know
Ten types of feature flags explained: Release flags, experimentation flags, operational flags, permission flags, and more.
How, when, and why you make features available to your entire user base can make the difference between success and failure.
In this blog post, we’ll explore the ten most popular types of feature flags so you know which ones to implement next time you’re ready to take new features for a test drive before they go live.
But first, let’s quickly review the concept of feature flags so we’re all on the same page.
What are feature flags exactly?
Feature flags are a software development tool that gives teams precise control over how and when new features are released to users.
They act as switches within the code that can be turned on or off without having to deploy new code. This means you can make features available to certain users, test variations of a feature, or even quickly disable a feature if problems arise.
10 types of feature flags
There are many types of feature flags, each with unique strengths and ideal use cases. This means you can tailor your feature management strategy based on each type.
Let's dive in and explore ten of the most common feature flags you should know:
1. Release flags
Release flags (also known as “release toggles”) act as a defensive barrier between the development and release of a new feature.
They allow you to deploy a feature's code to production without making it visible or accessible to users. Once thoroughly tested and approved, the flag can be switched "on" to unveil the feature to your audience.
Purpose: The goal of release flags is to separate the deployment of code from its actual release to users. This gives development teams greater control over the rollout process and reduces the risk associated with releasing new features.
Application: Release flags are often used for phased rollouts (gradually releasing a feature to different groups over time) and canary releases (testing a new feature with a small subset of users before a wider release).
Stakeholders: These feature flags are key for software engineers (they use them to merge and deploy code without directly impacting the user experience) and QA teams (they use them to test new features in a live environment before they’re fully released).
2. Experimentation flags
Experimentation flags enable you to expose different versions of a feature to distinct groups of users. This lets you see how these variations perform in the real world, collecting data on user behavior, engagement, and ultimately, the impact on your key business metrics.
Purpose: The purpose of experimentation flags is to gather data to inform decision-making. By running controlled experiments (like A/B tests), you can compare the effectiveness of different features or approaches and choose the one that drives the best results.
Application: These flags are commonly used for A/B testing (comparing two or more versions of a feature to see which one users prefer), algorithm optimization (evaluating the impact of algorithms on user behavior), and content personalization.
Stakeholders: Product managers (they define the goals and hypotheses for experiments and decide which variation to test), data analysts/scientists (they analyze the data collected to measure its impact), and engineers (they oversee implementation).
3. Operational flags
Operational flags are the control knobs for your system's inner workings. They don't directly affect what users see, but rather how the system itself behaves under different conditions.
These flags can be toggled on or off to adjust system-wide settings, helping you manage performance, diagnose problems, or adapt to unexpected situations.
Purpose: The main aim of operational flags is to give you granular control over your system's behavior without needing to change the underlying code or redeploy. This allows you to make real-time adjustments and respond quickly to incidents.
Application: Toggling maintenance modes (taking parts of the system offline for updates) and controlling logging levels (adjusting the detail of system logs to diagnose issues or monitor performance).
Stakeholders: DevOps teams (they use operational flags to manage system performance and troubleshoot issues) and system administrators (they may use these flags for routine maintenance tasks or to make adjustments to the system's configuration).
4. Permission flags
You can think of permission flags as the gatekeepers of your features. They determine who gets to see and use specific parts of your product, creating a tailored experience for different groups of users. This is done by linking features to specific user attributes, segments, or roles.
Purpose: The goal of permission flags is to provide granular control over feature access. This lets you offer exclusive features to premium subscribers, roll out features to a beta testing group, or hide features from users who don't meet specific criteria.
Application: Early access programs (granting select users access to new features before they go live), beta testing (an environment where users test features and give feedback), and subscription tiers (offering features based on a user’s subscription level).
Stakeholders: Product managers, customer success teams, and marketing teams.
5. Short-lived flags
Short-lived flags are temporary feature flags designed for specific, time-bound purposes. They have a clear start and end date, and are usually tied to a single release cycle or experiment. Once their purpose is fulfilled, they are removed to keep the codebase clean and maintainable.
Purpose: The main goal of short-lived flags is to provide temporary control and flexibility during a specific phase of development or testing. They help manage risk, gather data, or enable specific functionality for a limited time.
Application: One-time events (this means enabling or disabling features for special promotions, holidays, or limited-time offers), temporary experiments (i.e. short-term A/B tests), and hotfixes (rolling back a feature during a release cycle without redeploying).
Stakeholders: Product managers, QA teams, and software engineers (they create and manage the short-lived flags themselves).
6. Long-lived flags
Long-lived flags are designed to remain in the system for extended periods. While not permanent, they might persist for multiple release cycles or even months. They often control features that are still evolving or have ongoing testing requirements.
Purpose: The purpose of long-lived flags is to provide sustained control over features that aren't fully baked or require continuous monitoring. They can help manage risk by allowing for gradual releases, testing in production, or adjusting feature availability.
Application: Beta features (for longer beta testing periods than with short-lived flags), premium features (managing features that are only for specific users), and ongoing experiments (running long-term A/B tests, in stark contrast to the short-lived variant)
Stakeholders: Product managers, QA teams (for the same reasons as short-lived flags), and customer support teams.
7. User-based flags
User-based flags are like personalized switches that let you tailor the feature experience to each individual user. They are based on user attributes, such as location, demographics, or behavior, allowing you to offer a more customized and relevant experience.
Purpose: The goal of user-based flags is to personalize the user experience and make it more engaging. By adjusting features based on individual preferences and needs, you keep users happy and boost retention and conversion rates as well.
Application: Content personalization, A/B testing with user segmentation, dynamic pricing (adjusting prices based on user demographics or purchase history), and feature availability based on user roles.
Stakeholders: Product managers, data scientists/analysts, and marketing teams.
8. System-based flags
System-based flags react to specific system conditions or events. They are triggered by pre-defined rules or thresholds, allowing you to dynamically adjust feature behavior based on real-time data.
Purpose: The goal of system-based flags is to automate feature control and make your system more responsive to changing conditions. This can improve performance, enhance resource utilization, or prevent issues before they happen.
Application: Load balancing (adjusting feature availability based on system load), Failover mechanisms (switching to backup systems or features during outages or emergencies), and security measures (disabling features based on security threats).
Stakeholders: DevOps teams, system administrators, and software engineers.
9. Dynamic configuration flags
Dynamic configuration flags allow you to modify specific parameters or values within your code without requiring a new deployment. This gives you the ability to make real-time adjustments to the behavior of your application or features.
Purpose: The main goal of dynamic configuration flags is to let you change configurations on the fly. This allows you to respond to user feedback, adjust to varying conditions, or experiment with different settings without disrupting the user experience.
Application: Price adjustments, UI customization, and API rate limiting (dynamically adjusting the rate at which users can access APIs to prevent overuse or abuse.
Stakeholders: Product managers, developers, and marketing teams.
10. Kill switch flags
Kill switch flags are like emergency “stop” buttons for features. They let you quickly disable a feature if it's causing issues, without having to roll back an entire release or scramble to fix the problem in real time.
Purpose: The purpose of kill switches is to minimize the impact of unexpected problems. By providing a fast and easy way to turn off a malfunctioning or underperforming feature, you can prevent further damage.
Application: A new feature causing bugs, a feature not performing as expected and making customers unhappy, or a security vulnerability that’s been recently discovered in a feature.
Stakeholders: DevOps teams, software engineers, and incident response teams (they rely on kill switches to mitigate the impact of incidents and restore normal services as swiftly as possible).
Next steps
After carefully studying our list of ten types of feature flags, you should understand why they are so important. Now the challenge comes in the form of devising a smooth and swift implementation process.
That’s where using specialized feature flag software like Eppo becomes vital.
Eppo is an experimentation and feature management platform. Its goal is to make feature flag implementation a breeze so you can run experiments (like A/B tests) with ease.
Here’s how Eppo goes above and beyond simple feature flag management:
Bespoke tests and feature launches: Eppo lets you enable new features or run experiments for specific user segments. You can use parameters like demographics, device types, and user behavior to create much more focused tests or feature releases.
Safeguard your user experience with kill switches: Eppo's feature management lets you disable buggy features without having to roll back to a previous version, thanks to effective kill switches.
Reliable data for reliable results: Eppo integrates directly with your data warehouse (Snowflake, BigQuery, Redshift, etc.). This ensures you're experimenting with the most trustworthy metrics coming directly from your source of truth.
Smarter experimentation: With advanced statistical tools like CUPED++ (exclusive to Eppo) and sequential analysis, Eppo helps you find winning variations fast.
Quicker and more accurate experiments: Eppo offers a feature called contextual bandits which lets you craft unique experiences for your customers. This lets you make sure features are relevant to each user.
Ten types of feature flags explained: Release flags, experimentation flags, operational flags, permission flags, and more.
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