This Cloudflare app adds a simple text message at the top of your website if the visitor's browser version is too old.
If the visitor is using an Internet Explorer version less than or equal to specified in the app configuration, the message will appear, with a link to WhatBrowser.org. By default, this message will be displayed in IE8 and lower.
There are links to four different modern browsers at WhatBrowser.org, including the most recent version of user's current browser.
Note: Internet Explorer 9's Compatibility view will trigger the message, since the browser pretends to be an earlier version of Internet Explorer.
You can style the message however you want! All you need to do is add styles with id #cloudflare-old-browser. View source code for more details.
Additionally it adds class cloudflare-old-browser-body to document's body, if you'd like to push website's content down, so it won't be blocked by this message.
This app is opensource, so you are able to add a translation in your language simply by forking the repository on GitHub.
You may view source code of this app on GitHub.