Launched: Custom Targeting Rules

LaunchDarkly custom rules targeting with feature flags

A goal of LaunchDarkly is to provide our customers with the ability to target your users to meet the needs of your unique use cases.  We have always allowed you to target individual users or groups by any attribute that you define: name, e-mail, group, ID, country, age, etc.  However, we did not let you perform granular percentage rollouts for each attribute, nor did we allow you to construct conditional targeting rules. Many of you have asked for this!

Now, we are excited to launch custom targeting rules, allowing you to construct a conditional rule using a user attribute, operator, and value.

Use Cases

Using both boolean and multivariate feature flags, you can perform extremely powerful and granular user targeting:

  • Roll out a new feature to users who registered before a certain date
  • Perform a percentage rollout for all of your users who live in Canada and the United States
  • Release a feature to your beta testers whose e-mail address ends with
  • Turn on a VIP checkout system for all users who spend more than $100 per month
  • Release a new feature to 10% of users who belong to your Gold Plan and who signed up before August 1st, 2016
  • Target all of your users above age 35, and show the one-click checkout to 30%, the two-click checkout to 20%, and the original checkout to 50%.

Custom Targeting Rule

For a more concrete example, let’s say we have a feature flag that controls our app’s checkout flow.  This multivariate flag has three variations: one click checkout, two click checkout, and original checkout.  Here, we are performing a percentage rollout that targets all users whose email ends with or

LaunchDarkly feature flags and toggles using custom conditional targeting rules

Constructing a Rule

Let’s now build a rule using LaunchDarkly.  Here is a rule that serves the ‘true’ variation to all users whose e-mail address ends with

LaunchDarkly Custom Targeting Rule

You can target users by using any attributes that you send to LaunchDarkly, like group, country, age, and device.  For each feature flag, you can create as many custom targeting rules as you would like.

Additionally, you can add multiple conditions to a rule.  Users must meet all the conditions in a rule to match the rule. If any of the conditions are not met, the user will not match the rule.

Here, we’ve created a custom rule with two conditions. This rule serves true to all users whose e-mail address ends with “” and whose country is either “USA” or “Canada”.

LaunchDarkly feature flags / toggles custom rule with multiple conditions

If we want to do a percentage rollout instead, we can select “percentage rollout” from the dropdown and allocate users accordingly.  Here, we have are serving “true” to 25% of users whose ‘groups’ attribute is “beta_testers”.

LaunchDarkly feature flags / toggles percentage rollouts using attributes

There are many exciting ways to use custom rules, especially when you take full advantage of our multivariate feature flags.  If you have any questions or feedback, please send them to and we’ll be happy to help!

As a designer who can code, Justin can empathize with a developer's workflow and design intuitive interfaces to address extremely complex functionality. He has built dozens of user interfaces for high-traffic applications — winning the Best of California IT Design award in 2012. He frequently contributes feature flag management and design theory articles to DZone,, and DesignerHub. He holds degrees from UC Davis and USC, and is finishing an MS in Information Design at Northwestern. When he's not making developer's lives easier, he enjoys tennis, computer games, and writing.