Custom Traits

Custom traits are user or account traits collected from the Identify calls you send to Segment. For example, these could be demographics like age or gender, account-specific like plan, or even things like whether a user has seen a particular A/B test variation. From your sources, send custom traits as pieces of information that you know about a user in an Identify call.

As opposed to computed traits which are computed from your source data, or SQL Traits which are computed from warehouse data, custom traits are created from source events you pass into Segment and have no trait limits.

Comparing trait types

View the table below to better understand how Segment collects custom, computed, and SQL traits.

You can use the Profile explorer (Unify > Profile explorer) to view traits attached to a profile.

Using custom traits

Here’s the payload of a typical Identify call with custom traits (with most common fields removed):

{
  "type": "identify",
  "traits": {
    "name": "John Smith",
    "email": "john@example.com",
    "plan": "premium",
    "logins": 5
  },
  "userId": "97980cfea0067"
}

And here’s the corresponding JavaScript event that would generate the above payload:

analytics.identify("97980cfea0067", {
  name: "John Smith",
  email: "john@example.com",
  plan: "premium",
  logins: 5
});

Custom traits are mutable and update to the latest value seen by the user’s Identify events.

When an audience that previously generated Identify events is deleted, the data for the audience key is still attached to profiles that entered the audience and becomes visible in Segment as a custom trait.

Reserved custom traits

Segment has reserved some custom traits that have semantic meanings for users, and will handle them in special ways. For example, Segment always expects email to be a string of the user’s email address. Segment sends this on to destinations like Mailchimp that require an email address for their tracking.

Reserved custom traits Segment has standardized:

To learn more about using an Identify call to tie custom traits to profiles, visit Segment’s Identify documentation.