Check out our Getting Started Checklist to get the most out of LaunchDarkly.

After you create a LaunchDarkly account, you will have access to our Quickstart.  The Quickstart will walk you through the creation of your first feature flag using any of our SDKs.  You can use our Hello World sample app or create a sample feature flag in your own test environment.

Yes! While you will need a developer to integrate LaunchDarkly into your application, our dashboard allows non-technical team members to see how features are performing and toggle features without the need to rely on engineering. We strongly recommend you work closely with your developers to make sure that everything works appropriately.

LaunchDarkly is a continuous delivery and feature flag management platform built for teams. The platform allows companies to continuously deliver and deploy software to their users in a faster, more reliable way. You wrap your features in LaunchDarkly flags, which allows you to have full control over who sees the feature (users or user groups). It helps companies perform gradual feature rollouts, disable buggy features without redeploying, and reduce development costs with a more streamlined development cycle.

Feature flags are a software development best practice of gating functionality. Functionality can be deployed “off”, then turned on via the feature flag, separate from deployment. With feature flags, you can manage the entire lifecycle of a feature.

LaunchDarkly revolutionizes software development by allowing you to iterate quickly and safely. We allow you to easily flag your features, which enables you to manage them from the LaunchDarkly dashboard.

• Roll out a new feature to a subset of your users (like a group of users who opt-in to a beta tester group), gathering feedback and bug reports from real-world use cases.
• Gradually roll out a feature to an increasing percentage of users, and track the effect that the feature has on key metrics (for instance, how likely is a user to complete a purchase if they have feature A versus feature B?).
• Turn off a feature that you realize is causing performance problems in production, without needing to re-deploy, or even restart the application with a changed configuration file.
• Grant access to certain features based on user attributes, like payment plan (eg: users on the ‘gold’ plan get access to more features than users in the ‘silver’ plan). Disable parts of your application to facilitate maintenance, without taking everything offline.

Yes! We’ve made LaunchDarkly extremely developer-friendly and easy to integrate. You and your team can start controlling your first feature in minutes. We also provide excellent customer support to help you get started.

See our getting started guide.

Our unique streaming architecture ensures that feature flags are updated instantly, without introducing any latency to your site. LaunchDarkly’s performance is even faster than storing feature flags in your own database. We also have multiple layers of redundancy. All flags are served locally and are backed up by two layers of globally distributed CDNs. With the architecture, a feature flag will always be available.

Complete this form to schedule a free demo and we will be happy to demonstrate the platform and answer all your questions. Our feature flag platform is built to support both small and large development teams with enterprise-grade speed and reliability.

Yes!  We provide well-documented web and mobile SDKs for Java, JavaScript, PHP, Python, Go, Node.JS, .NET, Ruby, Python Twisted, iOS, and Android.  You can easily sync features across multiple platforms by using our SDKs throughout your stack.

Here is an article detailing the use case of syncing web and mobile user experiences.

View our SDKs

LaunchDarkly lets developers wrap features or application behavior in our feature flags. You can then manage your features on the LaunchDarkly dashboard, roll out to users, and see how well things are performing. LaunchDarkly gives you total control of your application.

• Turn features on and off for your users without waiting for engineering.
• Roll out to percentages of your population, segments, or whatever rules you define.
• Get faster feedback from the people you want. Measure the impact of your features with our NewRelic and Optimizely integrations.
• Create custom rules for granular targeting
• Manage configurations using our multivariate feature flags

LaunchDarkly supports both boolean and multivariate feature flags. A boolean flag has two variations true and false, which works best for feature flags that will simply turn things on and off. A multivariate flag allows you to define two or more custom variations. These variations can be strings, numbers, JSON objects, or JSON arrays. Check out the docs.

LaunchDarkly targeting lets you turn features on or off for individual users or groups of users. You can use the Targeting tab to roll features out for internal testing, private betas, or usability tests before performing a broader rollout. You can create your own rules to target who you want, when you want!

The Targeting tab allows you to roll a feature out to a percentage of your user base. For example, you can roll a feature out to 1% of users, then gradually scale up to 100% as confidence in the feature increases. LaunchDarkly’s rollouts ensure that a user will always see the same version of a feature until the rollout changes. Top tech companies have termed this a canary release – exposing features to some subset of users (whether it be opt-in, random rollout, or specific segments) is now used to describe what was once a beta.

• Microsoft: In development of Windows 10, Microsoft used “canary” releases to test with internal users within Microsoft. Gabe Aul, who leads the Data & Fundamentals Team in the Operating Systems Group (OSG), said “our Canary ring probably sees 2X-3X as many builds as OSG because we catch problems in Canary and don’t push to OSG.”
• Instagram: “Using ‘canary’ releases, updates go out to a subset of users at first, limiting the ability of buggy software to do damage.” Mike Krieger, Instagram co-founder and CTO, said he uses canary releases because “If stuff blows up it affects a very small percentage of people”.
• Google: For Chrome, Google offers Chrome Canary, which it labels with “Get on the bleeding edge of the web, Google Chrome Canary has the newest of the new Chrome features. Be forewarned: it’s designed for developers and early adopters, and can sometimes break down completely.”

In addition to targeting individual users, LaunchDarkly allows you to target segments of users by constructing custom rules.In other words, you can create custom rules to target users based on any attributes you send us.

Each rule has three parts: an attribute, an operator, and a user value.   You can create as many custom targeting rules as you want for each feature flag and even perform percentage rollouts for each rule.

All users that have not been individually targeted or who are not targeted by a custom rule will be evaluated by the default rule.

Learn more

LaunchDarkly provides you with a centralized dashboard to manage the lifecycle of your features from local development, to QA, to production. Manage multiple different software projects with their own development environments.

Projects allow you to manage multiple different software projects under one LaunchDarkly account. For example, you can create one project called Mobile App and another project called Web App. Each project will have its own unique set of environments and feature flags. By default, all team members in your LaunchDarkly account will have access to every project within that account.

Environments allow you to manage your feature flags throughout your entire development lifecycle — from local development to QA, staging, and production.

When you first sign up, you're provided with two environments within a project. By default, they're named Test and Production. Each environment has its own private SDK key, which is used to connect a LaunchDarkly SDK to a specific environment.

Each feature flag that you create has its own unique set of targeting rules for each environment. This means that you can change your flag rollout rules in a development or staging environment for QA testing before rolling out to production.

Using LaunchDarkly’s feature flags, you can separate feature rollout from code deployment, allowing you to slowly rollout a feature to a small percentage or subset of users in what is often referred to as a “canary release.” Canary launches allow you to quickly identify issues that might impact your entire user base, roll back easily to a known good version, and fix the issues in a controlled environment. The net result is a better product for all.

Canary releases, also called “soft launches,” give you the confidence to deploy. By giving you the control to roll out a feature and pull it back with minimum public attention, you can release something risky with the least possible fanfare.

You can also perform these types of releases during regular business hours. Gone is the Saturday 3 am deploy to ensure you disrupt as few users as possible. That is the power of feature flags. With LaunchDarkly, you can deploy a feature to 1% of your users on a Friday afternoon, wrapped in a feature flag. If something bad happens, it’s no problem. You can just flip the switch and the feature would be rolled back with only 1% of your users experiencing a few seconds of inconvenience.

In summary, with a completely scalable platform like LaunchDarkly, you can easily roll out features, see the reaction on your users, and either continue rollout or completely shut off.

See the use case page

LaunchDarkly allows teams to develop software in a way that’s fundamentally healthier, removing friction from the Product and Engineering relationship. The results are a dramatic savings in time and focus as well as faster delivery with greater trust.

Empowered product development means that both technical and non-technical team members can collaborate on software releases. Because feature rollout will be decoupled from code deployment, team members outside of Engineering would be able to control the visibility of particular features without compromising the app’s integrity. Product and QA teams are empowered to make changes to feature visibility without consuming engineering resources.

LaunchDarkly offers end to end feature flag management to allow an entire product development organization to control who gets the right feature, when.

• Facilitate coordination between Engineering and Product, allowing you to break up larger features into smaller deployments and release features faster to select customers
• Give control to the Product team, taking the burden of re-deploying off of engineering
• Reduce friction between teams, cultivating a healthier and more productive relationship

See the use case page

In most cases no— our streaming connection only requires that your server be able to make an outbound HTTPS connection to *.launchdarkly.com.

Almost nothing. LaunchDarkly’s SDKs use a streaming connection to asynchronously receive updates to your feature flag rules. Your actual feature flag requests are served from memory (or a Redis store, if you configure one). This adds less than 1 millisecond of latency to your page loads— about as fast as looking up a value in a hash table.

Yes, anonymous users are included in A/B testing. You will need to set an appropriate user key for anonymous users so that we can track each anonymous user separately; a session key might be appropriate. We don't display anonymous users on the Users screen because anonymous users couldn't be managed from LaunchDarkly, so they would only add clutter to the screen.

We'll never halt access or send you a weird bill based on overages. We allow for variance as we know a company's user base can grow unexpectedly over time.

Yes! All of our SDKs are built on top of the LaunchDarkly REST API. In fact, the entire LaunchDarkly web site is driven via the same API, so it’s heavily tested and complete. If you want to build a custom integration, export your data, or want to use LaunchDarkly on a platform that we don’t currently support, this API reference is the place to start.

You don’t have to send users to LaunchDarkly in advance – just set up your users in variation calls and you’re all set: http://docs.launchdarkly.com/docs/getting-started .

If we do not receive a request for a user in 30 days, then that user will no longer appear in the dashboard, but will still be stored in the database.   If we detect that the user is active again, then they will reappear in the dashboard with the latest set of attributes.  You cannot remove users manually from the dashboard.

You may add individual users using the LaunchDarkly dashboard by navigating to a feature flag and adding users manually in the targeting tab.

We use a z-score.

If you're seeing the "Your configuration is incomplete" message, it will usually indicate that there is an incomplete or invalid rule configured for your flag. For example, this could mean that an attribute was not selected, or a negative number was selected for a percentage rollout.

Make sure that you’re sending distinct user keys for each user in your variation calls. A few other possibilities:

• Your default rollout rule is serving a single variation
• Your users are receiving the fallback variation because something is not working correctly
• The kill switch was activated, and the feature is set to ‘Off’

Not currently, though we have a store abstraction that you can extend with your own storage backend like Postgres.

Exception:

Json parsing exception: java.lang.IllegalStateException: Expected BEGIN_OBJECT but was….ExceptionType: com.google.gson.JsonSyntaxException

Make sure your build tool is bringing in the proper version of Gson. The LaunchDarkly SDK may have problems with versions earlier than 2.2.4. To enforce the proper version add this dependency:

<dependency>
 <groupId>com.google.code.gson</groupId>
 <artifactId>gson</artifactId>
 <version>2.2.4</version>
</dependency>

Make sure your build tool is bringing in the proper version of the Apache http client. The LaunchDarkly SDK may have problems with versions earlier than 3.3.6. To enforce the proper version add this dependency:

The server SDK keys are intended to be embedded in trusted environments. The mobile SDK keys are suitable for use in (untrusted) mobile clients. If a mobile user were to somehow decompile your app, or gain access to your mobile key, there is really no impact, as those keys can only access a restricted subset of our APIs that do not reveal any private data.