That trailing slash DOES matter

I have been all bitter and twisted the past few weeks about Google putting some of my pages into the supplemental index.

And not just my rubbish pages, some of my best content has gone supplemental. After chewing on the problem for a couple of weeks, I have it figured out.

It's the trailing slash on my URLs, or lack thereof.

As odd as this may sound, is not the same as - in Google's eyes they are 2 different pages.

The supplemental index might look something like an unwanted pile of junk mail

Above: This basket of crap off my desk pretty well sums up what I think of supplemental results


One of my many supplemental pages is my spam-o-meter.
  • I know for a fact that the spam-o-meter drives a decent amount of traffic to this site
  • It's a good bit of link bait - that is, it has accumulated a respectable amount of links that I didn't have to ask for (just like Google recommends)
  • It's a PR6 page, respectable in anyone's book
  • has been online for almost a year so we aren't talking brand new or sandboxed
  • Ranks ok in the serps
  • Is not duplicated anywhere
  • Has no outbounds on the page
  • I haven't accumulated any links to this page from dubious sources

I'm pretty sure this page should not be lumped into the category of low quality and forgotten pages that is the supplemental index - or I'll really have to start questioning how much I know about this SEO game.

Want proof?

Check out the following URLs (sorry, I can't direct link them as my AJAX script will get all clever and fudge the URLs into something else). (PR6) (PR0)

My point is that the URL with the trailing slash is PR6 and the other is PR0. If that doesn't sway you, see if you can notice anything different in the following images, taken from a Google query...

No trailing slash equals supplemental index

No slash - and in the supplementals

With trailing slash equals main index

With the slash and it's all sweet

I am really careful at maintaining consistent link structure - I always use the trailing slash on my sites because I like it to feel consistent. But people who link to your site, are they as consistent? Unsurprisingly, people don't care about your trailing slash when they link to you - they go with what works. Googlebot follows these inbound links and indexes them - just like it's supposed to do.

What doe it all mean?

For me, having pages in the supplemental index is not good for credibility on a SEO related site. So now I have found out what the problem is.
Obviously, I want the result without the slash gone, so doing a 301 redirect is the obvious answer.

Does nobody else give a shit?

I think most people would agree this situation of having a version in the main index and a version in the supplemental index is not desireable. A 301 redirect would definitely fix the problem, and I actually did this in a prior version of my CMS.

At the time, I noticed many automated tools would break when accessing my site - they would often trip up on the 301 redirect. On top of that, most sites didn't seem to care about trailing slashes, so I decided I didn't need to care either and removed the redirect code.

Now when I take a look around, I see that the good sites do care about trailing slashes.
See what happens when you go to (note no trailing slash).
And notice how the Wikipedia shows a clear difference between a slash and no slash

I'm going to go with what Aaron Wall and Wikipedia do. 301 redirects on the no-slash pages it is!

Do you have pages in the Supplemental Index?

Enter the following query into Google. *** -sljktf should be replaced by your own site of course. This should bring up a list of the supplemental pages on your site.


I would humbly suggest you take a careful look at your site, if you use folder based URLs. I thought I knew a thing or two about how to prevent duplicate content, and I should have trusted my instincts instead of following the sheep.

I'll update this post when the changes are made - I fully expect Google to remove my supplemental results within a couple of weeks.
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Tags: 301301 redirectcontentpagerankredirectseo301 "301 redirect" content pagerank redirect seo