Understanding the Different Formats of device_id: UUID vs SHA-256

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The device_id in Mixpanel is used to associate events with the same anonymous user. It's automatically generated by Mixpanel's Web or Mobile SDKs and is local to the user's device. This ID will persist on all events tracked by that user on that device, until you call identify() or reset() methods. The format of the device_id can vary based on how it's generated. If you're tracking from servers, you'll need to generate and manage the IDs yourself. In such cases, Mixpanel recommends generating a UUID and storing that value in a cookie. This UUID can then be used as the device_id. However, the format of the device_id can also be influenced by other factors such as the specific implementation or the requirements of the system. For example, in some cases, you might want to use a hash of some unique ID of the user as the device_id for anonymizing users. In summary, the format of the device_id can vary based on the specific implementation and requirements of the system. Sources: - Anonymizing Users - Server-side Identity Management - Returning User

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