Using Underscores "_" In Your File Structure Can Actually Harm Your SEO Based Results

From a Search Engine Optimization perspective, using the underscore in your file structure or naming conventions is a bad idea. Everyone uses the underscore to make the file names, etc., more readable. Unfortunately, it has the exact opposite effect on the Search Bots. To them using an underscore is the exact same as using another number or letter. This means the underscore is not something that you should be using as a spacer.

As an example of what a Search Bot sees, lets look at "funsindthensunyresortshotel". It's rather difficult to make out the meaning of what that says isn't it? This is exactly how "fun_in_the_sun_resort_hotel" appears according to the Search Bots point of view. It is possible that the Search Bots will be able to figure out what you meant if you talk about the same thing on the page itself. However, instead of working to confuse the Search Bots, and potentially get lower Search Results because of it, why not simply find something that actually works as a proper spacer element?

There are only two things which can be used as spacers effectively (both from the Search Bot and Human point of view). These are the hyphen / dash "-" and the period / dot ".". Even though the dot can be used, it's not something that I would recommend because it's already being used in the file structure. Every file or sub-directory on a website uses the dot to set file names, etc. This can make it confusing for people if there are too many dots in a file name. For that reason it's best to avoid the dot as a general rule.

This leaves us with the dash which is actually a lot easier to work with than the underscore to begin with. If you use an underscore in a link which is displayed with an underline, the two blend together. That means people who may not know websites principles that well my actually think the underscore is a space. That will not only cause confusion, it can make it very difficult for your visitor to get to the page or file they are looking for. That means the underscore is potentially bad from the human point of view as well.

Let's take a moment to look at the same example used before with dashes in place of the underscores, "fun-in-the-sun-resort-hotel". This eliminates the confusion that can happen it is gets underlined, it's easy for people to read, and it even seems more friendly and inviting. So why then do so many people continue to use the underscore?

For most of the history of the internet the underscore and hyphen were seen as totally interchangeable. There was no difference between using one or the other. Many people used the underscore simply because it was seen as a little easier to read because it most resembles an actual space. Then because most of the professionals were using it, everyone else started to use it too. In this way the underscore is simply an old tool that has been used for a very long time.

Does this mean everyone should go out and change every web page, file name, etc., that used an underscore? The simple answer is that it depends on you. As said above, the Search Bots can separate the words even using the underscore. The problem is that it makes it harder for them to do so which may affect your Search Results. If you're already getting good results, then you probably don't want to touch anything. On the other hand, if you're not getting the results you want then you may want to make the change. Either way, if you do make changes then you will also likely need to play with 301 redirects (a whole other topic).

The point of all of this is that if you're going to create new pages, add web assets, or build entire websites; then you should stop using underscores and switch to the dash instead. It will give you the same results as the underscore without any of the potential complications that come with it.