I was asked yesterday, about whether you should use dashes – or underscores _ when renaming your attachments, images and setting up your Page URLs.
An important part of your on-page search engine optimization, is getting your URL structure and naming conventions correct.
Google has stated that you should be using dashes over underscores, because it affects how their search engine reads the keywords in your URL. For instance:
yourdomain.com.au/red-widget – Google sees that this URL is about “red widget.”
Yourdomain.com.au/red_widget – Whenever you use an underscore, Google combines the word. So, in this case, Google reads your intended keyword as “redwidget” with no space.
The same logic can be applied to images and pdf’s etc.
Optimizing your URLs by using dashes, and adding appropriate keywords will assist your rankings.
However, there’s no need to focus too much of your efforts on your URL structure because it doesn’t impact rankings as strongly as well written and quality content.