How to check if mod_deflate is enabled

Here are 2 links that allow you to check if mod_deflate is enabled:

port80’s tools

what’s my ip mod gzip tester

You can also use YSlow + Firebug but I ran into a strange problem where YSlow did not detect the compressed content (gave an F on gzip components) when I knew I was actually compressing content. I then looked around for other tools and found those 2 which detected the compression correctly. So lesson learned, use several tools to validate compression - just to make sure.