Twitter finally shut down its old platform theme on June 1, 2020, forcing all desktop users to use the new mobile-inspired layout. This happened after Twitter released its new user interface in July 2019, and starting in May 2020, it began displaying a warning that the old version of Twitter would be shutting down for everyone on June 1. While there were previously some workarounds to re-enable the old version of twitter.com by either changing the web browser's user agent to Internet Explorer 11 or removing the rweb_optin cookie, these no longer work. Since the old version of Twitter has been shut down, there's no point in switching to a web browser that's no longer supported or flipping the cookie , as the old theme is no longer available, and you'll end up with the error "This web browser is no longer supported."

Although Twitter no longer allows you to use the web client with the old layout, a Tampermonkey userscript called GoodTwitter2, developed by Bl4Cc4t, will restyle the new Twitter interface to make it look nice again. According to its creator, GoodTwitter2 is not a copy of the old design. After users install the userscript in Google Chrome or Mozilla Firefox using the TamperMonkey userscript manager, they will get the old navbar back, have their Twitter profile back on the left side of the interface, and will no longer have to use the new mobile-like layout on their desktop.

To install the GoodTwitter2 userscript on Google Chrome or Mozilla Firefox, users will first need to install Tampermonkey and then load the script from the GitHub by following these steps:
- Installation of Tampermonkey from the Chrome Webstore or the Firefox Add-Ons site. Click the link that will activate Tampermonkey to request an installation screen.
- Click on install and if you are using Chrome, the process ends here. Regarding Firefox users, they will have to trade security for convenience, because for the script to work, they also need to completely disable the Content Security Policy (CSP) by going to: config and changing the security.csp.enable flag to false.
CSP is a security that helps detect and mitigate Cross Site Scripting (XSS), clickjacking, and other data injection attacks that can lead to data theft and malware infections .Once installed, users can access GoodTwitter2 settings from within the Twitter interface by clicking their profile icon in the top right corner, going to “Security and Privacy,” and clicking the GoodTwitter2 entry under General Settings.
