The available data indicates a clear preference for using dashes (-) rather than underscores (_) in URLs for search engine optimization (SEO) purposes. While Google can technically interpret both, the source materials consistently recommend dashes as the superior choice for clarity, user experience, and potential ranking benefits. This article details the implications of this choice, drawing solely from the provided documentation.
Why URL Structure Matters
URL structure is not a direct ranking factor, but it influences user experience and provides signals to search engines about the content of a page. A well-structured URL informs users about the page’s topic and builds trust. Conversely, disorganized URLs with random characters can appear untrustworthy and negatively impact click-through rates (CTR). Google analyzes URLs to assess content relevance to search queries. The data emphasizes the importance of creating URLs that are simple, relevant, and match the page’s title or main idea.
Google’s Recommendation: Dashes as Word Separators
The source materials state that Google treats dashes as word separators, effectively understanding “men-leather-jacket” as “men leather jacket.” In contrast, underscores are not recognized as separators. One case study detailed a 18% increase in organic traffic, an 11% improvement in CTR, and a movement from page 2 to page 1 in average ranking position after a D2C fashion brand switched from underscores to dashes in its product URLs, implementing 301 redirects and updating internal links. Google documentation explicitly recommends using hyphens instead of underscores.
Domain Names and Dashes
While the use of dashes in domain names is not strictly forbidden, the data suggests potential drawbacks. Domain names with dashes can be harder for users to remember, increasing the risk of mistyping. Additionally, if a similar domain name without a dash exists, users may inadvertently navigate to a competitor’s site. The sources indicate that search engines give the same value to both hyphenated and non-hyphenated domains, but prefer accuracy, suggesting non-hyphenated domains are more valid. One source notes that adding a dash to a domain name can increase the likelihood of finding an available name if a preferred phrase is already taken. However, purchasing both the hyphenated and non-hyphenated versions of a domain is recommended to prevent traffic loss.
User Experience Considerations
The data highlights the importance of user experience (UX) in URL design. Short, clean URLs with dashes are easier to display on smaller screens, improving usability for mobile users. The presence of dashes can also aid in readability and prevent misinterpretation of domain names. One source cautions against using hyphens to create double meanings in domain names, as this can compromise website credibility.
Technical Implications and Best Practices
The documentation recommends avoiding dynamic parameters in URLs whenever possible, as they can result in long and unwieldy addresses. Shortening links for social media sharing may introduce these parameters, but they are not considered a significant threat. When changing existing URLs, implementing 301 redirects is crucial to preserve SEO equity and prevent traffic loss. Updating internal links to reflect the new URLs is also recommended. Resubmitting the sitemap via Google Search Console after URL changes is advised.
Underscores: Limited Acceptability
The source materials indicate that underscores are technically acceptable in URLs, but only in controlled environments such as internal development or tracking URLs. For public-facing pages intended for search engine indexing, dashes are the preferred choice. One source explicitly states that using underscores is a “bad practice.”
Addressing Potential Concerns
The documentation acknowledges that changing URLs can affect SEO, but emphasizes that proper implementation of 301 redirects can mitigate these risks. It also notes that while Google does not have a comprehensive, singular resource guide for SEO, it does provide guidance on URL structure within its broader documentation. The sources suggest that Google focuses its help center on technical implementation issues and actual SEO rules that could result in penalties, implying that the absence of a specific rule against dashes suggests their acceptability.
Conclusion
The available data consistently supports the use of dashes (-) over underscores (_) in URLs for SEO. Google recognizes dashes as word separators, improving content interpretation, while underscores are not treated as such. Implementing this practice, alongside proper 301 redirects and internal link updates, can lead to improvements in organic traffic, CTR, and ranking position. While dashes in domain names present some potential drawbacks regarding memorability and user error, they are not inherently detrimental to SEO. Prioritizing clear, concise, and user-friendly URLs with dashes is a recommended practice for U.S. businesses seeking to optimize their online presence.