RYEs is a browser extension that let's users convert text to speech, right at the comfort of their browsers. You will only need to install the extension on your browser.
Install for Chrome: https://chrome.google.com/webstore/detail/ryes/elkfmekgegbmelfnmaphepdipkflpcnf?hl=en-US
Install for Firefox: https://addons.mozilla.org/addon/ryes/