Check Customer isLogged in using knockout js magento 2.

You can check the customer is logged in or using knockout javascript in Magento 2 by using the ‘Magento_Customer/js/model/customer’ class.

customer.js file used to check customer is logged in or not.

Customer Js file contains the method isLoggedIn() to detect customer login status.

If a customer is logged in, return true otherwise return false. Create a JS file and check using the below code snippet.

/**
 * @author Rakesh Jesadiya
 */
define([
    'uiComponent',
    'Magento_Customer/js/model/customer'
], function (
    Component,
    customer
) {
    'use strict';

    return Component.extend({
        defaults: {
            template: 'Rbj_MyModule/custom-file'
        },

        /**
         * Check if customer is logged in
         *
         * @return {boolean}
         */
        isLoggedIn: function () {
            return customer.isLoggedIn();
        }
    });
});

I have called template custom-file.html using js. check using a template(.html) from custom-file.html by below way,

<!-- ko if: isLoggedIn() -->
    <div>Customer is logged in</div>
<!-- /ko -->

Output: Boolean