Feature flags offer an excellent way to quickly turn off and on product changes by enabling you to remove and add the code in the software quickly. Marketers or product managers can choose a time and moment to make a feature or function live to win that aha moment.

The feature flags are helpful to various departments, including marketing, product, testing, CROs, and development. The number of feature flags can rise quickly as the team realizes their helpfulness and begins to utilize them. To avoid the mismanagement it may create, you need feature flag platforms. A comprehensive space where you can place all your feature flags and manage, modify, and delete them.

Finding a tool that fits the exact needs and requirements of developers, marketers, and product managers can be challenging. But don’t worry; we have done the heavy lifting for you. In this article, we have curated a list of the 10 feature flag tools and their best features. We've also covered the common functionalities you should look for when selecting tools for your team.

What are feature flag tools?

A feature flag tool, also known as a feature management or feature toggle tool, is a software or platform designed to facilitate the implementation, management, and control of feature flags in software applications. These tools provide a centralized interface or API that allows developers and teams to easily create, deploy, and monitor feature flags without directly modifying the underlying codebase.

To understand feature flags tools, let’s summarize what feature flags are first.

Feature flags, also known as feature toggles or feature switches, are software development techniques used to enable or disable certain features or functionalities in an application or system. They allow developers to control the release and availability of specific features to different user segments or environments without the need for code deployments or separate branches.

Do feature flag platforms help?

Yes. Feature flag platform comes with a range of features, including centralized flag management, an easy-to-use interface, user segmentation, traffic allocation, and integration with other tools to simplify the process of using feature flags in software development.

Feature flag platform enables you to:

• Gradually roll out new features: Release features to a small percentage of users and gradually increase rollout for feedback and risk mitigation.
• Perform A/B testing: Run experiments exposing different feature variations to user segments to determine optimal performance.
• Enable feature toggling: Dynamically enable or disable features without code changes for flexible control over feature availability.
• Rollback problematic features: Quickly deactivate features causing issues and revert to a stable state to maintain system stability.
• Trunk-based development: Merge the code to the main branch without releasing it to production.
• Personalize user experiences: Customize user experiences based on attributes, roles, or preferences to enhance satisfaction and engagement.

For a non-tech person, doing it all using CLI and code could be confusing & challenging. Plus, as you continue to create and use, you will have many feature flags, which could lead to mismanagement. Having a feature flag tool helps you there.

Popular feature flag tools

InfraCloud DevOps, platform engineering, and software development teams extensively use feature flags. So, we asked them which tools they preferred and why.

We uncovered many feature flag tools, both open source and commercial. The ‘best’ depends on the project requirements and engineers' preferences. However, there are still basic features that a feature flag software must have. Here, we have shortlisted feature flag software covering fundamental features and advanced capabilities for specific use cases.

For now, let’s see the best feature flag tools:

1. FeatureHub
2. Unleash
3. Flipt
4. Growth Book
5. Flagsmith
6. Flagd
7. LaunchDarkly
8. Split
9. ConfigCat
10. CloudBees

Let's discuss each of them in detail.

1. FeatureHub

(Image src: FeatureHub)

FeatureHub is a cloud-native feature flag platform that allows you to run experiments across services in your environment with a user-friendly interface — FeatureHub Admin Console. It comes with a variety of SDKs so you can connect FeatureHub with your software. Whether you are a tester, developer, or marketer, you can control all the feature flags and their visibility in any environment.

If you are looking for a tool that focuses more on feature and configuration management, FeatureHub may be the better choice. Its microservices architecture allows for greater scalability and extensibility, and it provides advanced features such as versioning, templates, and the ability to roll back changes.

Features of FeatureHub:

• Open source version available
• SaaS in beta version
• Google Analytics/RBAC/AB Testing
• Supported SDK included Python, Ruby, and Go
• OpenFeature is in process
• SSO support
• Community support & documentation
• Dedicated support to SaaS users

2. Unleash

(Image src: Unleash)

With 10M+ Docker downloads, Unleash is a popular and widely used open source feature flag platform. As it supports Docker images, you can scale it horizontally by deploying it on Kubernetes. The platform's intuitive interface and robust API make it accessible and flexible for developers, testers, and product managers alike.

However, the open source version lacks several critical functions, such as SSO, RBAC, network traffic overview, and notifications. However, you can integrate these features using other open source solutions.

If you are looking for a tool that focuses more on feature flagging and targeting, then Unleash might be the better choice for you. Unleash provides more advanced capabilities for user targeting, including the ability to target users based on custom attributes and the ability to use percentage rollouts. Additionally, it has a wider range of integrations with popular development tools, including Datadog, Quarkus, Jira, and Vue.

Features of Unleash:

• Open source version available
• AB Testing/RBAC/Targeted Release/Canary release
• SDK support for Go, Java, Node.js, PHP, Python etc
• OpenFeature supported
• Community support and documentation
• Premium support for paid users
• Observability with Prometheus

3. Flipt

(Image src: Flipt)

Flipt is a 100% open source, self-hosted feature flag application that helps product teams to manage all their features smoothly from a dashboard. You can also integrate Flipt with your GitOps workflow and manage feature flags as code. With Flipt, you get all the necessary features, including flag management and segment-wise rollout. The platform is built in the Go language and is optimized for performance. The project is under active development with a public roadmap.

Features of Flipt:

• Only open source version
• No SaaS
• Support for REST & GRPC API
• Native client SDKs available in Go, Ruby, Java, Python etc.
• OpenFeature supported
• SSO with OIDC & Static Token
• Observability out of the box with Prometheus & OpenTelemetry

4. GrowthBook

(Image src: GrowthBook)

GrowthBook is primarily a product testing platform for checking users' responses to features. It is relatively new, and the SaaS version is much more affordable than other SaaS-based feature flag platforms. SDKs from GrowthBook are available in all major languages and are designed not to interfere with feature flag rendering.

You can easily create experiments using GrowthBook's drag-and-drop interface. Integrations with popular analytics tools, such as Google Analytics and Mixpanel, make tracking experiments easier for better results. If you run many A/B experiments and do not want to share your data with 3rd party apps, GrowthBook could be an amazing option as it pulls the data directly from the source.

Features of GrowthBook:

• Open source version available
• SaaS version available
• A/B Testing/unlimited projects
• SDK support for React, PHP, Ruby, Python, Go, etc
• Observability via Audit Log
• Community support and documentation

5. Flagsmith

(Image src: Flagsmith)

Flagsmith is another open source solution for creating and managing feature flags easily across web, mobile, and server-side applications. You can wrap a section of code with a flag and then use the Flagsmith dashboard to toggle that feature on or off for different environments, users, or user segments.

Flagsmith offers segments, A/B testing, and analytics engine integrations that are out of the box. However, if you want real-time updates on the front end, you have to build your own real-time infrastructure. One of the best parts of the Flaghsmith is the Remote config, which lets you change the application in real-time, saving you from the approval process for the new features.

Features of Flagsmith:

• Open source version available
• SaaS product available
• A/B Testing/RBAC/Integrations with tool
• SDK support for RUBY, .NET, PHP, GO, RUST, etc
• OpenFeature support
• HelpDesk for community support
• Docker/Kubernetes/OpenShift/On-Premise (Paid)

6. Flagd

(Image src: Flagd)

Flagd is a unique feature flag platform. It does not have a UI, management console, or persistence layer and is completely configurable via a POSIX-style CLI. Due to this, Flagd is extremely flexible and can be fit into various infrastructures to run on various architectures. It supports multiple feature flag sources called syncs like file, http, gRPC, Kubernetes custom resource, and has ability to merge those flags.

Features of Flagd:

• Only open source version is available
• Progressive roll outs
• Works with OpenFeature SDK
• Technical documentation
• Lightweight and flexible

7. LaunchDarkly

(Image src: LaunchDarkly)

LaunchDarkly is a good entry point for premium feature management tools as it is not expensive comparatively but offers many useful features. It enables you to easily create, manage, and organize your feature flags at scale. You can also schedule approved feature flags to build a custom workflow.

One of the features of LaunchDarkly is Prerequisites, where you can create feature flag hierarchies, where the triggering of one flag unlocks other flags that control the user experience. This way, you can execute multiple feature flags with one toggle. With multiple integration options available, including API, SDK support, and Git tools, you can automate various tasks in LaunchDarkly.

If you are looking for paid software with quality support and a comprehensive set of features, LaunchDarkly could be your option.

Features of LaunchDarkly:

• No open source version is available
• SaaS product only
• A/B Testing/Multiple variants testing
• SDK support for Go, Gatsby, Flutter, Java, PHP etc
• OpenFeature supported
• Academy, blogs, tutorials, guides & documentation
• Live chat support

8. Split

(Image src: Split)

Split brings an impressive set of features and a cost-effective solution for feature flag management. It connects the feature with engineering and customer data & sends alerts when a new feature misbehaves. With Split, you can easily define percentage rollouts to measure the impact of features.

There is no community support, but the documentation is detailed and organized. Once you move ahead of the slight learning curve, you can easily organize all your feature flags at scale with Split.

Features of Split:

• No open source version
• SaaS-based platform
• A/B Testing/Multi-variant testing/Dimension analysis
• SDK support for Go, Python, Java, PHP etc
• OpenFeature supported
• Blogs, guides & documentation
• No on-prem solution
• Free plan available

9. ConfigCat

(Image src: ConfigCat)

ConfigCat enables product teams to run experiments (without involving developer resources) to measure user interactions and release new features to the products. You can turn the features ON/OFF via a user-friendly dashboard even after your code is deployed.

ConfigCat can be integrated with many tools and services, including Datadog, Slack, Zapier, and Trello. It provides open source SDKs to support easy integration with your mobile, desktop application, website, or any backend system. One fantastic feature of this software is Zombie Flags – which identifies flags that are not functional or have been used for a long time and should be removed.

Features of ConfigCat:

• No open source version is available
• SaaS product
• % rollouts, A/B testing/variations.
• SDK support for Go, Java, Python, PHP, Ruby etc
• OpenFeature supported
• Blogs, documentation & Slack community support

10. CloudBees

(Image src: CloudBees)

CloudBees is not a dedicated feature flag management platform, but it allows you to manage feature flag permissions and automate cleanup easily. While having a dashboard helps, CloudBees also offers bidirectional configuration as code with GitHub to edit flags in your preferred environments.

The dashboard's sleek and intuitive design makes it easier for developers and DevOps teams to use and leverage its functionalities. However, the software has so many features that it could be a slight challenge to learn all of them.

Features of CloudBees:

• No open source version is available
• SaaS product
• A/B Testing/Multiple variant testing
• SDK support for Java, Python, C++, Ruby etc
• OpenFeature supported
• Blogs, video tutorials, & documentation

Quick comparison of the feature flag tools

Open the sheet to have a comparison of feature flag tools in a glance.

What should you look for in a feature flag tool?

There are so many feature flag tools, but these are the features you must look for when picking a platform.

1. Community support

Proper support is crucial to overcoming the initial onboarding challenges, whether for an open source or proprietary product. Some OSSs have an extensive community, documentation, blogs, and user-generated content to help and educate the next generation of users. The OSS product's creators, maintainers, and experts often offer commercial support. For example, at InfraCloud, we offer Linkerd support, Prometheus support, and Istio support because our engineers are proficient in these technologies.

For closed source products, you can get video tutorials, blogs, documentation, and live chat, and most importantly, you can raise a ticket and solve your problem quickly. Not having a proper support channel can leave you in the middle during an emergency. So, analyze your requirements to see what kind of support your team needs, whether they can do it with the help of documentation or need hand-holding.

2. Integration

It is critical for the successful feature flag process that the programming languages used to develop the products are well supported by the feature flag platform. If the language is not supported, enough resources should be available to connect your product and feature flag platform.

Going with platforms that support OpenFeature could be a good solution. As OpenFeature provides a vendor-agnostic, community-driven API for feature flagging that works with your favorite feature flag management tool. You would not have to change the application code much in case you plan to change it later.

In the list, I mentioned the feature flag platforms that support the most common and popular development languages and are OpenFeature friendly. When selecting a feature flag platform, don’t forget to analyze your tech stack to find whether the feature flag is compatible. Otherwise, a major chunk of time might go into developing the integrations between the technology used and the feature flag platform.

3. 3rd Party Apps

What if you could view and monitor feature flags and approval requests from your team's Slack workspace or use Terraform to configure and control the feature flags?

All this and more is possible if the feature flag offers integrations. You can bring integrations by wrangling scripts and making an automation process that works on triggers. But here, we picked the software with native integration abilities to streamline & automate the feature flag operations further.

4. Easy-to-use UI

Feature flags are not always used by developers. Often, product marketers like to have control over the lever that launches the features to the public. In case of any issue, marketers and product managers can quickly kill the feature that makes the product unstable from the platform without waiting for the developer.

So, having an easy-to-use user interface is a key characteristic when selecting a feature flag tool. Some open source feature flag platforms have a rudimentary design covering basics, and some are fully-fledged platforms with incredible UX and tutorials at every corner.

In the list, we covered the software that has a usable UI.

5. Testing & reporting

New features can be tested using the feature flags. Sophisticated feature flags tools come with various testing methods, including A/B/n and blue-green deployment strategy. Functions like setting up variable and controlled factors, allocating traffic, and insights from the result are extremely helpful in delivering a product feature confidently.

With feature flag tools, you can segment the users and roll the features accordingly to test the initial responses. The software also comes with dashboards to see the results of the experiments. You can view all the requests and how users spend time using the software with newly released features.

These tools include testing and reporting features, making it easy to run experiments and make data-backed decisions.

FAQs related to feature flag tools

What are the different types of feature flags?

There are several types of feature flags commonly used in software development:

• Boolean flags: These flags are the simplest feature flags based on a true/false value. They enable or disable a feature globally across all users or environments.

• Percentage rollouts: Also known as "gradual rollouts" or "canary releases," these flags allow features to be gradually released to a percentage of users. For example, a feature can be enabled for 10% of users initially, then gradually increased to 25%, 50%, etc.

• User segmentation flags: These flags enable features for specific user segments based on predefined criteria such as user attributes, roles, or subscription levels. They allow targeted feature releases to specific groups of users.

• Feature toggle flags: Feature toggle flags provide more granular control over the behavior of a feature. They allow different variations or configurations of a feature to be activated or deactivated dynamically.

Who uses feature flags?

Software development teams, including developers, product managers, and DevOps engineers, widely use feature flags. They are particularly beneficial in agile and continuous delivery environments, where iterative development, experimentation, and frequent releases are essential.

What are feature flags' limitations?

While feature flags offer numerous advantages, they also have some limitations to consider:

• Increased complexity: Introducing feature flags adds complexity to the codebase and requires careful management to avoid technical debt and maintainability issues.

• Performance overhead: Feature flags introduce conditional checks that can impact performance, especially when numerous flags are evaluated at runtime.

• Flag proliferation: Over time, the number of feature flags may grow, leading to potential confusion, maintenance challenges, and increased technical debt.

• Testing effort: Feature flags require additional testing efforts to ensure the functionality of different flag combinations and variations.

What is the difference between a feature gate and a feature flag?

The terms "feature gate" and "feature flag" are often used interchangeably, but they can have slightly different connotations. A feature gate typically refers to a more granular control mechanism that checks whether a specific user has access to a particular feature, usually based on permissions or user roles. On the other hand, a feature flag is a broader concept encompassing various flags used to control feature availability, behavior, or rollout.

What is a feature flag rollback?

Feature flag rollback refers to deactivating a feature flag and reverting the system's behavior to a previous state. It is typically used when a feature causes unexpected issues, performance problems, or undesirable outcomes. The system can revert to a stable state by rolling back a feature flag until the underlying issues are addressed.

What is feature flag hygiene?

Feature flag hygiene refers to best practices and guidelines for managing feature flags effectively. It involves maintaining a clean and manageable set of flags by periodically reviewing and removing obsolete or unused flags.

Final words

Finding the best feature flag platform isn’t easy, especially when you have many great options. While all these tools are great, you must factor in your requirements to find the best fit.

We hope this list helps you find the best platform to manage feature flags. This article is developed with the contribution of Faizan, Sagar, Bhavin, and Sudhanshu. You can reach out to any of them if you need answers to any of your doubts.

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