How to detect broken, dead rss feeds in google reader

A simple trick, I wanted to share in google reader.

Go to the Trends page:


Select the "Inactive" tab in "Subscription trends":

There you have it the list of somehow inactive feeds.

The top 3 reasons why those feeds may be inactive are:

• the blog doesn't exist anymore (404)
• the blog changed it's engine and the feed url is not the same (for ex: the blog moved from jroller to wordpress, it is hosted somewhere else...)
• there hasn't been any post for a really long time

Advise for the blogger reading this:

• Try to avoid at all cost changing the feed url
  
• When it's not possible write a last post saying the url is changing before changing it otherwise nobody will notice it and therefor you are loosing all your readers