Twitter has started testing a new desktop website based on their mobile website that should be a faster experience.
If you're not lucky enough to be included in this A/B test, you can "break" into it by setting the rweb_optin cookie to on.
You can do that by pasting the following URL into your browser's address bar while you're logged-in on https://twitter.com.
javascript:document.cookie%3D'rweb_optin%3Don%3B%20expires%3D01%2F12%2F2019%3B%20path%3D%2F%3B'%3Bwindow.location.reload()%3B
Safari might prevent you from pasting javascript into the URL bar. In which case, you need to enable that feature.
Firstly, turn on developer mode in Safari's advanced preferences – "Show Develop menu in menu bar". Then, under the Develop menu, check "Allow JavaScript from Smart Search field".
If you're concerned about pasting arbitrary javascript into your browser, that URL was produced by the following code
`javascript:${encodeURIComponent("document.cookie='rweb_optin=on; expires=01/12/2019; path=/;';window.location.reload();")}`;And it simply runs the following javascript
document.cookie='rweb_optin=on; expires=01/12/2019; path=/;';
window.location.reload();