Identifying External Links – Like Wikipedia

Wikipedia - External Link Identification

I found myself wondering a while back how Wikipedia identifies external links the way they do. I’ve seen the same concept on many other sites, but I had never really looked into how it was done. I always just assumed that an image was dynamically added to any code that included external links.

It turns out that I was wrong, and I was kind of happy to find that out. The answer I found makes much more sense, and is much more simple to implement.