Detect IE - Need Help For Work

Check here if you are using an IE: codepen

I need to detect if a user is using an IE or an other browser.
The problem is, that I only have on my office computer the IE11.
Is there someone how has an older IE version and can check if this works?

Thanks

I find this useful tool : https://netrenderer.de/

Now I found out that it is impossible to visit codepen with older IE Versions -.-

I think the best way to do this is to use the Modernizr library. It takes care of the detection for you and is well tested.