Before diving into the subject of URL Taxonomy Optimisation, it’s important to clarify its position and role within the broader URL Optimisation practice. At its core, URL Optimisation can be split into:
- URL Taxonomy Optimisation: Optimising the categorisation of all URLs on the website with particular reference to Taxonomic Depth and Topic Clusters, as explored in detail below.
- Page URL Slug Optimisation: Optimising the fragment of URL that identifies one particular landing page and is largely limited to the effective use of keywords, as part of Onpage Optimisation.
- Domain Name Actuation: The segment of the URL containing the Protocol, optional Subdomain (including the Canonical Domain), the Domain Name and the top-Level Domain, typically optimised once for the entire website.
- Dynamic URLs Optimisation: An alternative to the optimisation of static URLs comprised of Page Slugs and URL Taxonomy, Dynamic URLs is a topic explored separately in SEO.
Understanding the role of URL Taxonomy Optimisation and how it fits within the wider URL Optimisation framework may prevent time-consuming follow-up fixes to preventable issues.
Table of Contents
Defining URL Taxonomy
URL Taxonomy Optimisation entails crafting a reflection of the website’s Information Architecture in the URL Structure. A logical URL Taxonomy supports search engines in understanding the thematic relevancy of landing pages, the relationship between them and in relation to the wider web.
- Taxonomic Depth: Taxonomic Depth reinforces the website’s information architecture by defining the position of each landing page as part of a vertical hierarchy.
- Navigational Orientation: Nested URLs provide users with essential context regarding a page’s Parent Topic, allowing them to identify their current location within the website hierarchy and interact more freely with the wider information context.
- Parent-Child Relationships: The taxonomy establishes a clear relationship between Parent and Child pages, acting as a map for crawlers to trace a granular page back to its Parent Page.
- Authority Signals: Search engines assign higher authority to Parent Pages. The closer a page is to the root domain and the more relevant content is nested under it, the stronger the topical signal becomes for the entire website.
- Topic Clusters: Topic Clusters support the grouping of semantically-related content under topic-indicative subdirectories to cultivate Topical Relevancy and earn Topical Authority in the eyes of search engines.
- Topical Relevancy: Grouping related landing pages under a subdirectory helps search engines understand the semantic context of a website subdirectory as a whole, ensuring that the collective context of the subdirectory reinforces the relevancy of every individual URL within that path and vice versa.
- Topical Authority: Search engines use the breadth of interlinked, relevant landing pages within a cluster to determine the website’s expertise. This “holistic” context allows crawlers to assign higher ranking potential to individual pages, as they are backed by a comprehensive network of content covering different aspects or angles of a subject.
By combining Taxonomic Depth with Topic Clusters, the URL structure moves beyond simple organisation to become a clear signal of expertise. This alignment ensures that search engines do not just see isolated pages, but instead recognise the website’s complete Topical Map. Ultimately, the clarity brought forward through the URL Taxonomy helps search engines place the website in closer alignment with relevant keywords and possibly better organic search rankings.
Build Topic Clusters using Subdirectory Keywords
Keywords placed in a subdirectory slug provide a broader topical signal than keywords placed in the page slug:
- Optimising the Page Slugs establishes Topical Authority for the entire subdirectory they’re nested under
- Optimising the Subdirectory Slug establishes Topical Relevancy for all Pages nested under it.
This hierarchical alignment creates a bi-directional flow of authority between general topics and niche details. For instance, URL Taxonomy Optimisation is clearly pinned down as a component of the broader URL Structure Optimisation, which is itself nested under the wider topic of Technical SEO.
Subdirectory Depth
While search engines can crawl deep hierarchies, the best practice is to limit it to two to three levels of Subdirectories. Beyond this depth, the URL string becomes unintelligible to users and often truncated in SERPs. Every additional subdirectory should only be employed if it adds clear semantic value that cannot be captured by a more restrained structure.
https://wordprexeo.com/search-engine-optimisation/onpage-optimisation/url-optimisation/url-structure-optimisation/url-path-optimisation/By nesting keywords this way, you ensure that every individual page contributes to a unified signal of expertise. In turn, this collective authority flows back down the URL path, reinforcing the organic ranking potential of every landing page within the Topic Cluster. This synergy makes it easier for search engines to trust and rank your entire website as a cohesive, authoritative resource.
URL Taxonomy in WordPress
In practice, to place a URL under the subdirectory of an existing published page on the website, you can specify it as a Parent Page.
Specifying the Parent Page in WordPress
- Make sure you’re in the Backend Editor for the right Page.
- Open “Page Settings” and find the “Parent” input field.
- Select the “Parent Page” you’d like to serve as a subdirectory for the page you’re editing.
- In this case, /url-taxonomy/ will be placed under the existing /url-structure-optimisation/ subdirectory.
You can also edit the Parent Page using the “Quick Edit” feature on the “All Pages” or “All Posts“. Just find the Page or Post > “Quick Edit‘ > Parent.
As a result, the URL for the URL Taxonomy will communicate to both users and search engines that the content on this page is a subtopic of URL Structure.
https://wordprexeo.com/technical-seo/url-structure-optimisation/url-taxonomy/Using Topics Instead of Calendar Dates in Subdirectories
Although dates are acceptable in URLs under select circumstances, most of the time using dates in URLs isn’t the right choice. The exception to using dates is when the content on a landing page might be time-bound and searched using keywords incorporating dates, thus making the dates a relevancy signal for search engines about the landing page.
However, the use of dates in other cases is generally an inferior way of structuring content as the a published date provides limited context to search engines or users about the semantics of the content behind the URL.
Changing the Permalinks Settings in WordPress
If you have your Post dates displayed in the URL as subdirectories by default, it’s likely because of your Permalinks structure settings in WordPress. Your Permalinks structure settings allow you to specify the variables WordPress will use to automatically name the URLs when creating new Posts.
To change your Permalinks settings in WordPress navigate to WordPress’ main “Settings”, then click “Permalinks” which will open the “Permalinks Settings‘” window and set the Permalinks Structure to “Post name”. This way you will have search engine optimised URLs by default.
URL Structure Optimisation Best Practice
URL character length
From a technical point of view, URLs must be shorter than 2,083 characters in order to correctly render in all browsers. Additionally, in order for a page URL to display fully in SERPs, as opposed to it being truncated, its length should be within the limits of 512 pixels. The actual number of characters will, of course, vary as some characters spread over more pixels than others. A general estimate for URLs to fully display in SERPs would fall at around 50 to 60 characters.
Use short URLs
While individual URL slugs should be concise, the length of a subdirectory name is of even greater structural importance. Because a subdirectory string is used on every nested URL within that structure, a long-named subdirectory exponentially increases the risk of SERP truncation for all underlying URLs.
- Avoid using superfluous words that do not add immediate value to the content, like prepositions and conjunctions [https://wordprexeo.com/onpage-optimisation/
optimisation-of-imagesimage-optimisation/]. - Avoid the repetition of keywords that are already present in the Parent Pages of the current subdirectory [https://wordprexeo.com/technical-seo/url-structure-optimisation/url-taxonomy
-optimisation/]. - Keep the length of any given subdirectory slug or page slug within three words, otherwise it becomes unintelligible to users who are less likely to rely on it to make a decision about the context of the landing page it represents.
There is a negative correlation between the length of a URL and organic search rankings, meaning that all things being equal, shorter URLs are likely to rank higher in organic search results.
URLs Paths are case-sensitive, meaning a subdirectory with uppercase letters [https://wordprexeo.com/technical-SEO/] is a different subdirectory than one with the same letter in lowercase [https://wordprexeo.com/technical-seo/]. Despite uppercase letters generally being allowed in URLs, WordPress applies certain URL sanitisation rules, which will automatically convert all uppercase letters to lowercase to prevent various issues caused by case-sensitivity being handled differently across systems.
The use of non-English characters in the URLs of non-English websites is allowed and in case of subdirectories, encouraged. Even though non-English characters require encoding, browsers and search engines typically display international characters as decoded. Also, most search engines can recognise, crawl and rank web pages based on the keywords containing such international characters. So, if one expects users to search for keywords containing non-English characters, it is only normal to make appropriate use of them in URLs.
WordPress URL Sanitisation
WordPress typically employs URL Sanitisation which is a practice of automatically adjusting URL slugs to prevent common potential issues.
- Automatically converts latin alphabet characters with diacritics [á] into the standard English characters without diacritics [a].
- Aautomatically uses appropriate encoding for the characters from all other alphabets. The encoded characters are typically decoded and displayed normally in both browsers and search engines and their encoded URL segments are only revealed when copied to clipboard.
URL Paths, including Subdirectories support both, Hyphens [-] and Underscores, however the hyphen [-] is now the only recommended option for filling-in space between words. The reason behind this is that search engines are programmed to read the hyphens [-] as word separators, while the underscores [_] as a means of combining words. As a result, the use of underscores [_] is now discouraged altogether.
When it comes to URLs, not all characters are born equal. It begins with a group called Unreserved Characters. The most commonly used characters in URLs are alphanumerics (a-z and 0-9). There’s also a small number of additional special characters including the hyphen [-] used to separate words, the underscore [_] traditionally used to combine words, the dot [.] and the almost equals sign [~].
On the other end, there are Reserved Characters, which possess a reserved technical purpose within a URL Path. In other words, their appearance in a specific part of the URL has the technical capacity to change its semantics. The full list of reserved characters include: ! * ‘ ( ) ; : @ & = + $ , / ? % # [ ].
Reserved characters can be used without encoding when employed for their reserved purpose. Although they can also be outside their reserved purpose (with encoding), WordPress URL Sanitisation usually strips these characters from URL Slugs. In other words, if your URL Slug contains these characters, WordPress will automaticall remove them.
The Forward Slash [/] reserved purpose
The character with arguably the most important reserved purpose in URLs is the forward-slash [/], used on subdirectories [/subdirectory/]. In simple terms, forward slashes [/] enable all URLs to be part of a hierarchy, by delimiting separate entities on a website from each other. An entity that is contained between 2 forward slashes [/] in a URL is called a Subdirectory [/subdirectory/], while the last entity that is contained within one or multiple Subdirectories is referred to as a Landing Page.
Some subdirectories can employ the role of landing pages. In other words, while the URL subdirectory [/subdirectory/] serves as the portion of the URL that precedes the portion of the landing page [/sub..ry/landing-page-1/], it may also host a langing page of its own under that Subdirectory slug.
Technical aspects aside, the notable difference between a subdirectory and a landing page is that Subdirectories are typically employed to store multiple landing pages, the content of which have related semantic meaning.
The hash sign [#] reserved purpose
An important feature in URLs is triggered by the use of hashes [#], which normally indicates not only the location of the page but also a specific location within the page itself, such as a header or the beginning of a paragraph on that page. This is particularly useful for information-heavy websites, which may require to accommodate hyperlinks to specific paragraphs or sections of text as opposed to the entire landing page. The content of such URLs with hashes [#] is always crawled and indexed part of the main URL [without #] and will not rank on its own.
URLs can not contain blank spaces. More specifically, WordPress URL Sanitisation automatically converts the blank spaces entered in the URL slug field into hyphens [-].