where does mixpanel web sdk store the device id info in the browser ?

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The Mixpanel Web SDK stores the device ID (the $device_id property) in the browser using either localStorage or cookies, depending on your configuration. By default, the SDK uses cookies for persistence, but you can configure it to use localStorage by setting the persistence option to "localStorage" when initializing the library: LBKSmixpanel.init('YOUR_PROJECT_TOKEN', { persistence: 'localStorage' });LBKSIf you require cross-subdomain tracking, you should use the default cookie persistence, as localStorage does not support cross-subdomain access. Disabling persistence entirely (with disable_persistence: true) will prevent the device ID from being stored, which also disables anonymous-to-identified user tracking and super properties Quickstart FAQ.In summary, the device ID is stored in either a cookie or localStorage, based on your SDK configuration.

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By default, the Mixpanel cookie—which stores the device ID and other super properties—has an expiration value of 365 days. You can change the cookie's lifetime by setting the cookie_expiration configuration option during initialization. For example, to set the cookie to expire in 90 days: LBKSmixpanel.init('YOUR_PROJECT_TOKEN', { 'cookie_expiration': 90 });LBKSThis will adjust how long the device ID and other super properties persist in the browser cookie Setting Super Properties.

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