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User identification

Turn anonymous visitors into persistent and searchable profiles along with custom parameters.

Visitor profile and journey

Profiles track your users with persistent IDs (like email or userId) and provide several advantages:

  • Cross-platform tracking: Follow users across browsers and devices
  • Search visitors: Find specific users and their journeys in your analytics dashboard
  • Persistent tracking: Maintain user journey even if cookies are reset
  • Better attribution: Link anonymous traffic to known users

How to identify a user

Use the window.datafast() method to identify a visitor:

window?.datafast("identify", {
  user_id: "unique-user-id", // required
  name: "John Wayne", // optional - if present, it will replace the anonymous name in the visitor profile
  image: "https://example.com/avatar.jpg", // optional - profile image URL
  // ... any other custom parameters you want to track
});

Required parameters

  • user_id (string, required): A unique identifier for the user like email or userId

Special parameters (optional)

  • name (string): If present, it will replace the anonymous name in the visitor profile
  • image (string, 250 char. max.): A valid URL pointing to a profile image to display in Journeys and the Realtime Map. Example: https://lh3.googleusercontent.com/-WuQbhWk1Xso/AAAAAAAAAAI/AAAAAAAAAAA/ALKGfklNb9VSEpE-xxOXfgy6n9NGIdz-2g/photo.jpg?sz=46

Custom parameters validation rules

  • Property names: lowercase letters, numbers, underscores (_), and hyphens (-) only. Max 64 characters.
  • Property values: any string, max 255 characters.
  • Limits: maximum 10 custom parameters.

Add this script to your HTML <head> to guarantee identification is captured even when triggered before the main script loads:

<script id="datafast-queue">
  window.datafast = window.datafast || function() {
    window.datafast.q = window.datafast.q || [];
    window.datafast.q.push(arguments);
  };
</script>

Example usage

useEffect(() => {
  if (user && user.email) {
    window?.datafast("identify", {
      user_id: user.email,
      name: user.name,
      image: user.profileImage,
      role: user.role,
      plan: user.plan,
    });
  }
}, [user]);

Note: User identification is separate from custom goals. Use identify to link users to their accounts, and use custom goals to track specific user actions.

Special notes

  • Persistent tracking: You need to identify the visitor each time their cookie changes for persistent tracking. You can call window.datafast("identify") every time their session changes.

  • Revenue attribution: If revenue attribution is present, we automatically identify the customer using data from the payment provider.

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