When you have a web page with a lot of information, it can be tempting to link to every article you ever wrote about that topic. But too many links on one page may be a bad thing.
In most cases the recommended maximum is 100 links on any one page. This number is credited to Matt Cutts from a post on Webmaster central where he said “Keep the links on a given page to a reasonable number (fewer than 100).”
The key here is to make it reasonable. If you have a page that is referencing all your articles on a topic, then include as many links as you need. But for most pages, links are useful, but not critical. About.com has a recommended ratio of 1 link for every 250 words on a page.
Links and SEO
When you add links to any one page, search engines like Google traverse the page and follow the links. Those links would then get some of the PageRank applied to the current page passed on to them. But they only get a fraction of the PageRank, depending upon how many links there are.
So if you have a page that has good PageRank, you can pass that high rank on to pages you link to it. But it's best to limit the links to as few as possible, so that the PageRank that is passed is as high as possible.
Links and User Perception
The other reason you need to limit your links is because too many links makes a page look spammy. This is especially true if you have several words in a row linked to different pages in your content blocks. The more links you have in one paragraph of text, the more spammy your page will look.
I recommend limiting your paragraphs to only 3-4 links. On a page with 10 paragraphs, that will only be at most 40 links, which leaves 60 left for navigation and standard site links.
What About Navigation?
The other thing that many content developers forget is that built-in links count. In other words, if you're aiming for fewer than 100 links per page, you have to count the links in your navigation and in other parts of your site template as well.
When search engine spiders look at web pages they don't make a distinction between links in the content and links elsewhere on the page. And often, your readers won't either. A page with 50 “blogroll” links in the sidebar is going to look just as spammy as a page with every other word linked.
The Bottom Line—Don't Worry Too Much
If adding another link adds value to the page, then you should do it. Your goal for any page you post on the web is to make sure that it provides the best possible experience for the readers.
Google is not going to penalize you if your page has 101 (or 301) links. In the past, Google would only index about 100K of any given page, and since links add more to the page size, limiting links made sense. But since at least 2009, Google has been indexing much more than 100K on pages. And so adding more links is not going to hurt you.
Here are some situations where a lot of links makes sense:
- An index
- Reference pages
- Content hubs
Just make sure that there is a reason for the links and that the links are relevant to the page as a whole. If you do that, then you could have 1,000 links on the page and you'd be okay.