Historically, “feature flag” and “feature toggle” have referred to the same fundamental concept: a runtime control mechanism used to enable or disable specific functionality within a software product without deploying new code.

For the vast majority of teams and products, there is no functional difference between a feature flag and a feature toggle. Both refer to runtime controls that allow teams to manage feature exposure in production.

However, in some contexts, subtle distinctions may emerge to differentiate between:

• Binary switches/toggles (on/off, true/false)
• Multi-variant flags (flags with multiple values or variants, not just on/off)
• Conditional or dynamic flags (features activated based on rules, user segments, or environments)

Even in these cases, the distinction is contextual rather than universal. The choice of terminology typically reflects company culture, historical usage, or product branding rather than a technical architectural distinction.

Why the concept matters more than the name

The purpose of these runtime controls is far more important than the terminology. What matters is the capabilities they provide and why this has become critical for modern software organizations.

The need for runtime control

Despite decades of improvement in DevOps, CI/CD, and agile processes, high-profile software failures continue to occur. Major outages and costly downtimes often result not from faulty deployments, but from a lack of real-time control over feature exposure.

Feature flags address this by enabling teams to:

• Decouple deployment from release: Ship code to production in a safe, controlled state without immediately exposing new functionality to users.
• Gradually release features: Enable new capabilities for targeted user groups, minimize “big-bang” releases, and validate incrementally.
• Instantly roll back: If issues arise, disable only the problematic feature rather than rolling back entire deployments.
• Run experiments and A/B tests: Test variants and measure impact across business, engineering, and customer dimensions.
• Reduce risk: Limit the blast radius of any change and enable feedback-driven, safe releases.

Consider a financial services company rolling out a new payment processing feature. The team has spent months developing and testing the functionality, which integrates with sensitive core banking systems.

Without feature flags: The feature is merged into the main branch and deployed to production after passing automated tests. However, a critical edge-case bug discovered only with real user data puts customer transactions at risk. The team’s only recourse is a full rollback of the deployment, taking down unrelated improvements and causing hours of downtime.

With feature flags: The code is deployed behind a feature flag. The rollout targets only internal staff initially. Monitoring tools observe real transactions, revealing the bug before customer accounts are affected. The rollout is paused, the flag remains off for customers, and debugging continues. Once the fix is verified, the feature is incrementally enabled for a segment of users and ultimately the general population.

This example demonstrates why the capability to control features at runtime is essential—regardless of whether it’s called a flag or a toggle.

Types of feature flags: Why “toggle” isn’t always accurate

A “toggle” implies a binary (on/off) switch. In reality, mature feature management systems support a range of flag states and behaviors:

• Binary feature flags: Enable or disable a capability. Example: Show or hide a “Dark Mode” UI option.
• Multi-variant flags: Choose from several versions or configurations. Example: Serve three different recommendation algorithms to different user cohorts.
• Conditional flags: Activate features for specific users, geographies, devices, or percentage rollouts.
• Gradual rollout flags: Slowly increase exposure from a small cohort to the entire user base, monitoring for problems at each step.

In modern platforms like Unleash, the distinction between binary and multi-variant is a matter of configuration, not terminology. You might configure a “multi-variant flag” or a “percentage rollout flag,” but they’re all managed as feature flags at the platform level.

Calling every flag a “toggle” can be misleading if it supports more than two states or complex logic. “Feature flag” remains the most general and precise term.

The bigger picture: Feature management as operational practice

Understanding feature flags in isolation is insufficient for today’s technology landscape. Modern feature management recognizes that feature delivery is not just a technical tool, but a central operational and business practice.

Modern feature management turns feature delivery into a controlled, measurable, and adaptable process that connects deployment velocity with business impact:

• Flags serve as the runtime primitives that enable controlled feature delivery.
• Full-stack experimentation becomes possible when you can target, measure, and control features across the stack.
• Features can be tied to strategic metrics—revenue, stability, customer satisfaction—and managed through their entire lifecycle, including cleanup and archiving.

Don’t get distracted by the terminology. Instead, focus on architecting robust feature management practices—adopting proper lifecycle processes, investing in experimentation capabilities, and ensuring you have the runtime control essential for safe, efficient software delivery.

In the end, call it a flag, toggle, or switch—but make it the foundation of how your team delivers and governs software in production.

FAQ: Feature flags and toggles

What is the difference between feature toggles and feature flags?

For most practical purposes, there is no functional difference between feature flags and feature toggles. Both terms refer to the same fundamental concept: a runtime control mechanism used to enable or disable specific functionality within a software product without deploying new code. While “feature flag” emphasizes the concept of a marker indicating whether a feature should be active, and “feature toggle” points toward the idea of a switch that can be turned on or off, they are used interchangeably in informal conversations. Most organizations tend to use “feature flag” as the standard term.

What is the difference between feature flags and configuration?

Feature flags are a specific type of configuration that focuses on controlling the visibility and behavior of features at runtime. While general configuration settings might control system parameters, connection strings, or application behavior, feature flags specifically enable or disable functionality, control access to features, or determine which variant of a feature users see. Feature flags are dynamic configuration values typically designed to be changed without requiring a deployment, allowing for runtime control over application behavior.

What is the point of a feature flag?

Feature flags serve several critical purposes in modern software development:

• They decouple deployment from release, allowing code to be shipped to production without immediately exposing new functionality
• They enable gradual release of features to targeted user groups
• They provide the ability to instantly roll back problematic features without rolling back entire deployments
• They facilitate experiments and A/B tests across different dimensions
• They reduce risk by limiting the impact of changes and enabling feedback-driven, safe releases
• They provide runtime control over feature exposure, enhancing safety and flexibility

What is the difference between feature flags and feature branches?

Feature branches are a version control strategy where developers create separate branches in the code repository to develop new features isolated from the main codebase. Feature flags, on the other hand, involve integrating code into the main branch but wrapping it with conditional logic that controls whether the feature is visible or active at runtime.

The key differences are:

• Feature branches isolate code during development; feature flags integrate code but control exposure
• Feature branches require merging code to expose functionality; feature flags require toggling a runtime switch
• Feature flags allow for targeted rollouts, instant rollbacks, and experimentation that branching strategies alone cannot provide

Is it a feature flag or a feature toggle?

Both terms refer to the same concept and are used interchangeably in the industry. While some vendors or organizations might make subtle distinctions between them (with “toggle” sometimes implying a binary on/off state and “flag” sometimes encompassing more complex multi-variant configurations), there is no universal standard differentiating the terms. “Feature flag” has become the more commonly used umbrella term that encompasses binary switches, multi-variant flags, and conditional flags.

To feature flag or to not feature flag?

Feature flagging is highly recommended for any software that:

• Serves a significant number of users
• Requires high availability
• Needs controlled, gradual rollouts
• Benefits from experimentation and A/B testing
• Has mission-critical components where failures would be costly
• Undergoes frequent updates and releases

Not feature flagging introduces risks of costly rollbacks, extended downtime, limited ability to test in production, and all-or-nothing releases. However, feature flags do require management to avoid technical debt, so teams should consider implementing processes for flag lifecycle management.

How does one differentiate between a feature flag and an authorization role?

Feature flags and authorization roles serve different purposes but can sometimes appear similar:

• Feature flags control functionality availability based on release strategy, experimentation needs, or operational concerns. They determine whether a feature exists in the running system.
• Authorization roles control access based on user permissions, security requirements, or business rules. They determine whether a user can access a feature that exists.

While both can result in features being shown or hidden to specific users, they have different purposes: feature flags are primarily for release management and experimentation, while authorization is for access control and security. In a well-designed system, feature flags would determine if a feature is enabled in the system at all, while authorization would determine who can access that enabled feature.