One of the challenges we have as an agency is working with clients who want to link to absolutely everything from their global navigation. A business owner or marketing manager often has a hard time deciding what is more and less important -- to them it's all important! This results in a bloated navigation that detracts from the SEO value that those internal links pass through the site in the form of PageRank.

To help better explain the SEO side of this we created an internal link juice tool to show very clearly how much PageRank link juice flows through each link on the site, and then compare that to how much link juice would flow if the number of links were reduced to 100 links. This suddenly turns nebulous talk about best practices into hard numbers that make it much easier to understand the importance of prioritizing what links really deserve a spot in the navigation or the home page.

How the Tool Works

The tool is very simple: just head to the internal link juice tool and enter a URL into field, fill in the PageRank of the page, and go. The tool will then go check the number of links on the page. It will calculate the total amount of PageRank link juice the page has to distribute and show how much link juice each link is passing. If the site has more than 100 links, it will also show how much juice each link would pass if the number of links were reduced to 100. Finally the tool lists all of the links that it found on that page. If the link is an image, it pulls in a thumbnail of the image so you know can see what it is. This part in particular helps respond to the shocked, "There's no way I have that many links on my page!"

The tool also has a Manual tab where you can just enter any PageRank value and quantity of links. This is useful for seeing exactly how changing the number of links affects the PageRank juice passed through each link.

For those interested in the math, here's how the tool crunches the numbers. We started by assigning a PageRank 1 page an arbitrary link juice value of 100. SEOmoz has reported that each increase of one PageRank represents about a nine-fold increase in total PageRank link juice, so we increase that link juice value nine-fold with each PageRank (and this tool lets you appreciate how quickly that grows). Based on the PageRank paper, we then assume that only 85% of a page's link juice flows outward, which is the total link juice of the page. Finally we just divide that number by the number of links. A PageRank 0 page is assigned 15 link juice to pass along, representing the fact that all pages pass some amount of PageRank link juice.

PageRank: Does it Even Matter?

Of course this brings up the question of how much we really want to focus on PageRank, or draw client's attention to the metric. We know that PageRank is just one of hundreds of algorithmic ranking factors and that toolbar PageRank is not the actual PageRank that's used anyway. On the other hand we also know that PageRank is still a ranking factor with some weight. I prefer to educate clients as much as possible on what matters and how much, but I also understand the desire to just hide the info from clients to keep them from fixating.

Matt Cutts has said that organizing links for purposes of passing PageRank internally is beneficial, but not a top factor (of course the top factor he repeatedly cites is creating great content). From his video:

"So imagine you've got two different pages: you got one product that earns you a lot of money every time someone buys, and you got another product where you make, you know, ten cents. You probably wanna highlight this page [the lot of money page], you wanna make sure that it gets enough PageRank that it can rank well, so this is more likely to be a page that you wanna link to from your homepage.

"I do think that having more links because you have great content is a better way to rank well because it's a second order effect to be sculpting your PageRank. It can be useful but it wouldn't be first thing that I would do."

The best independent science we have on the impact is explained by Rand in the Science of Ranking Correlations where SEOmoz found that toolbar PageRank has a positive correlation to ranking, though a small one. Specifically it had a correlation of 0.18 (slightly better than mozRank, but worse than external mozRank). For reference a correlation of 0.00 would mean there is no correlation, and the highest correlated ranking factor, Page Authority, had a correlation of 0.28 according to the SEOmoz 2011 ranking factors.

Best Practice: is it Still 100 Links per Page?

For a long time the best practice in SEO web design was to have no more than 100 links on any given page. We originally got this number from Google themselves, but that number is now much more flexible. As Matt Cutts explains in this video, the original 100 links per page guideline was based on old limitations in how much Google could actually index and this limitation no longer exists.

What this means is that having more than 100 links on a page will not penalize your site in rankings, will not necessarily trigger a spam penalty, and all of those links will get indexed. However, every additional link is still reducing the overall amount of PageRank that passes through each link, which can in turn reduce the PageRank the linked pages have. As we saw above, PageRank is still a ranking factor, and fewer links means more PageRank, which means better rankings.

This is covered well by Dr. Pete’s How Many Links is Too Many article, where he said, “There’s an inescapable reality in SEO that the more links a page has, the less internal PageRank each of those links passes.”

At Ecreativeworks, we’ve seen real impact from refining global navigation with our own clients. Logically the more links a site has bloating the global navigation, the greater a ranking benefit we see from pruning those links Here’s a recent example from January:

A large manufacturing company we began working with had over 600 links in their global navigation, largely due to drop-downs and tiered flyouts (four tiers deep). We shut down all of their flyouts past the first tier and refined the dropdowns to only what was really important. We cut the total number of links in the global navigation to only 64 – a reduction of over 500 links (per page). A bit over a month later many of their key rankings – those category pages in the global navigation – improved substantially, many improving by a full page and an average improvement of 7 ranks (many going from page 2 to page 1). Interestingly the rankings for the pages removed from the navigation did not fall, because with so many links in the global nav virtually no PageRank was flowing through each one anyway.

This is a great example because it's so extreme, but we regularly see a similar boost from many sites. As long as there is a substantial change in navigation links, we see a corresponding change in the ability of the linked pages to rank. Another recent client just dropped their global navigation from 176 links to 74 links, and two weeks later are already seeing ranking improvements of 2 to 5 ranks across nearly every keyword being tracked.

Less is More with Internal Links

The 100 links per page guideline is still a good one, but isn't set in stone. There is no magic number of links. You should try to have the fewest number of links that provides a good user experience – but usability always comes first. Every link you remove increases the juice passed by the remaining links ever so slightly, and in quantities it adds up to meaningful improvements.

Here are a couple of useful examples:

• SEOmoz has only 75 links on their home page.
• Amazon.com usually has around 200 links on their home page.
• Target.com, in contrast, has around a whopping 1,000 links on their home page.
• Wikipedia English language main page has around 300 links, including the links to the other language versions.

I like the Amazon.com and Wikipedia examples, because there are very few sites out there that are truly larger or cover more topics and products than these two sites. You would need to talk pretty fast to convince me that your site really needs more links than they do, or indeed that it needs nearly as many as they do.

As a final note on the topic, be aware that nofollowing links does not change this equation. Nofollow links still reduce the overall amount of PageRank that flows from each link, even though nofollow links do not pass PageRank themselves. Adding the nofollow tag to internal links does not help you rank in any way.