Medium Member script to inject a button that automatically redirect to free version of the original post

freemium.js

// ==UserScript==
// @name         Medium to Freedium Redirect with Button
// @namespace    http://tampermonkey.net/
// @version      2024-09-23
// @description  Insert a button to redirect Medium posts to an alternative free version.
// @author       Cristiancast - https://github.com/Cristiancastt
// @match        https://medium.com/*
// @match        https://*.medium.com/*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=medium.com
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    // Function to create and insert the button
    function insertRedirectButton() {
        // Remove existing button if present
        const existingButton = document.querySelector('.freedium-redirect-button');
        if (existingButton) existingButton.remove();

        const button = document.createElement('button');
        button.className = 'freedium-redirect-button';
        button.textContent = 'Read on Freedium';

        // Apply button styles
        const style = document.createElement('style');
        style.textContent = `
            .freedium-redirect-button {
                appearance: none;
                background-color: #2ea44f;
                border: 1px solid rgba(27, 31, 35, .15);
                border-radius: 6px;
                box-shadow: rgba(27, 31, 35, .1) 0 1px 0;
                box-sizing: border-box;
                color: #fff;
                cursor: pointer;
                display: block !important;
                font-family: -apple-system, system-ui, "Segoe UI", Helvetica, Arial, sans-serif;
                font-size: 14px;
                font-weight: 600;
                line-height: 20px;
                margin: 10px;
                padding: 6px 16px;
                position: fixed;
                top: 60px;
                right: 20px;
                text-align: center;
                user-select: none;
                z-index: 999999;
                opacity: 1 !important;
                visibility: visible !important;
            }
            .freedium-redirect-button:hover {
                background-color: #2c974b;
            }
            .freedium-redirect-button:focus {
                box-shadow: rgba(46, 164, 79, .4) 0 0 0 3px;
                outline: none;
            }
            .freedium-redirect-button:active {
                background-color: #298e46;
            }
        `;

        // Ensure style is added only once
        if (!document.head.querySelector('style[data-freedium-styles]')) {
            style.setAttribute('data-freedium-styles', 'true');
            document.head.appendChild(style);
        }

        // Add click event to redirect to freedium
        button.addEventListener('click', function() {
            const currentUrl = window.location.href;
            let freediumUrl;

            // Check if URL contains subdomain.medium.com pattern
            if (currentUrl.match(/https:\/\/[^.]+\.medium\.com\//)) {
                // Remove the subdomain part and replace medium.com with freedium.cfd
                freediumUrl = currentUrl.replace(/https:\/\/[^.]+\.medium\.com\//, 'https://freedium.cfd/');
            } else {
                // For regular medium.com URLs
                freediumUrl = currentUrl.replace('medium.com', 'freedium.cfd');
            }

            window.location.href = freediumUrl;
        });

        // Insert the button into the body
        document.body.appendChild(button);
    }

    // Function to check if we're on a Medium page
    function isMediumPage() {
        return window.location.hostname.includes('medium.com');
    }

    // Function to initialize the button
    function init() {
        if (isMediumPage()) {
            // Small delay to ensure the DOM is ready
            setTimeout(insertRedirectButton, 1000);
        }
    }

    // Run on initial page load
    init();

    // Create a more robust observer for SPA navigation
    let lastUrl = location.href;
    new MutationObserver(() => {
        const url = location.href;
        if (url !== lastUrl) {
            lastUrl = url;
            init();
        }
    }).observe(document, { subtree: true, childList: true });

    // Also check periodically in case the observer misses something
    setInterval(init, 5000);
})();