URL Structure for airTRFX Pages

Enmanuel Tirado
September 07, 2023
8 min read

What Are URLs?

URL stands for Uniform Resource Locator, and it’s basically the address of a resource on the Internet.

An URL can be broken down essentially into four parts:


  • Protocol: "https://" indicates the method that the browser must use to request the resource. For a website, the most common methods are HTTP (hypertext transfer protocol) and HTTPS (HTTP secure).
  • Domain or hostname: "airline" the name of the website.
  • Top-level domain (TLD): ".com" indicates the domain type (e.g.: .edu for educational; .com for commercial; .gov for governmental). It can also declare the target geographic region. For example, .gb targets UK while .us targets US. These are called Country Code Top-level Domain (ccTLD). TLDs that don’t specify the target region are called Generic Top-level Domain (gTLD). 
  • Path: "en-us/flights-to-miami" it’s everything that follows the TLD, including folders, parameters, and anchors. 

The Subdomain vs. Subfolder Debate: Which is Better for SEO?

Although Google has said that it’s fine to use either subdomains or subfolders, this remains a hot topic in SEO. Before getting dragged into the debate, let’s first define what a subfolder and a subdomain are.

  • Subfolder: a subfolder (also known as a subdirectory) is part of the root domain and houses a specific subset of content. A subfolder sits to the right of the main domain. Example: https://airline.com/flights

To implement airTRFX pages via a subdirectory, the airline core website needs to be delivered through a Content Delivery Network (CDN). This way, we will be using Reverse-Proxy connected to EveryMundo servers. 

  • Subdomain: a subdomain is a “child” or a partition of the main domain. A subdomain sits to the left of the main domain. Example: https://flights.airline.com/

To implement airTRFX pages via a subdomain, the airline will create a subdomain and point a CNAME record to EveryMundo sub-domain.

From these definitions, there is a key fact you must know: Google treats subdomains as different sites, separate from the main domain. This means that Google treats URLs on a subfolder as part of the main domain, while URLs on a subdomain are treated as part of a “different” website. 

To better understand the nuances of the subdomain vs. subfolder debate, let’s consider the context from the SEO perspective. There are two known important ranking factors in Google’s algorithms:

  • Content
  • Links

Because Google treats subdomains as separate websites, the content and links hosted on the main domain won’t be taken into account when Google’s algorithms are assessing the subdomains, and vice-versa. This implies that a brand-new subdomain will need to earn “overall authority” to Google’s eyes from scratch. 

The other downside of subdomains, compared to subfolders, comes from “backlink dilution”. Basically, it means that when external sites link to the main site, such links won’t help the subdomain because, you guessed it, the subdomain it’s treated as a separate website. 

Aside from direct ranking factors, there may be technical challenges to maintaining and promoting subdomains, which could have implications for SEO. For example, if, due to some technical issue, the main site can’t have internal links to the subdomains, it wouldn’t help! 

While subfolders have added SEO benefits in many scenarios, in our opinion, subdomains shouldn’t be entirely disregarded.

There are instances where subdomains may be a better choice:

  • The content is totally different from the main domain’s content. E.g.: https://careers.airline.com
  • The technical infrastructure won’t allow the implementation of subfolders to host the content (i.e. customer does not use a CDN). 
  • The content will be managed through a CMS that can’t be installed on subfolders. 
  • Legal restrictions require hosting the content on subdomains. 
  • Subdomains are not considered in the USDOT/WCAG requirements.
  • For branding purposes, some airlines may want to create a separate subdomain for sections of the website. E.g.: https://support.airline.com

For airTRFX, we recommend the subfolder implementation. Hosting airTRFX pages on subfolders comes with the added SEO benefits:

  • Google will discover and index the airTRFX pages faster.
  • airTRFX pages will “inherit” the “overall authority” of the main domain (the airline’s core website). 
  • airTRFX pages will benefit from the backlinks that the main domain may acquire over time. 
  • airTRFX comes with the technical infrastructure to properly manage content in subfolders.  

We have also seen remarkable positive results for customers who have migrated airTRFX from a subdomain to a subfolder implementation. For example, the graph below shows the visibility gains for a major carrier after a subdomain to subfolder migration:

Screenshot 2023-09-07 at 9.05.03 AM.png

Does the airTRFX URL Structure Need to Match That of the Core Website?

It’s not necessary for the airTRFX pages to match the URL structure of the core website. In fact, Google has said that URLs don’t need to match the folder structure at all. 

Many of our implementations across +80 customers have a different URL structure from that of the core website. We haven’t found any downside or negative impact among these implementations. 

URL structures on airTRFX perform equally well, regardless of what the URL structure of the airline website is. 

Additionally, for subdirectory implementations, customers must define rules for the CDN to route the traffic from the customer's servers to EveryMundo. Those rules specify unique URL patterns (typically defined via regex), which allow the servers to identify which pages need to be routed to EveryMundo servers. For this reason, the URL of the airTRFX pages must utilize a different pattern from the customer's core site to avoid conflicts with the airline's existing URLs.













Core Website Example URLairTRFX Example URL

Does Google Favor a Specific URL Structure?

This is a question that we often get from our customers, and the answer is NO. As we explained earlier, the URL is only one ranking factor out of hundreds, and it alone does not determine a site’s ranking in search. 

This is also evident from the search results you get when you use keywords with purchasing intent on Google. Here are a few examples:

Screenshot 2023-09-07 at 9.08.08 AM.png

Screenshot 2023-09-07 at 9.10.59 AM.png

As you can see, there is a mix of URL structures in search results.
For the “flights to Miami” keyword:

  • Kayak - multiple folders in URL.
  • Expedia, Tripadvisor, Travelocity, Cheapflights, Hotwire, Orbitz - No subfolders in the URL path.
  • American Airlines, United Airlines - country and language codes followed by URL path with no subfolders.

For the “flights from Miami to Chicago” keyword:

  • Kayak, Expedia, Orbitz, Skyscanner - multiple folders in URLs.
  • Tripadvisor - No subfolders in the URL path.
  • Cheapflights, Cheapoair, Southwest - Single subfolder in URL
  • American Airlines, United Airlines - country and language codes followed by URL path with no subfolders.

The key takeaway is that SEO is more than just URLs, and this is also true for airTRFX. However, based on our experience with more than 60 customers, we feel pretty confident in recommending our default URL structure for airTRFX pages. 

Are URLs Important for SEO?

It’s no secret that URLs are a ranking factor, but there’s no clear answer to whether they play a major role in Google’s algorithms. Google has indicated that websites should “make URLs that work for users, not for SEO”, which implies that URLs may be a minor ranking factor

Still, optimizing URLs for SEO and users remains a rule of thumb because:

  • URLs are still a ranking factor.
  • A descriptive URL provides both users and search engines clues about the page content
  • URLs may indicate how a website site is structured. 
  • When crawling a page for the first time, Google uses the keywords in the URL to classify the page content, which can help the page rank better and faster. 
  • URLs are especially important for multi-language SEO because they can indicate the target country/language of the website or pages. 
  • Optimized URLs improve click-through rate in search results.
  • A well-crafted URL facilitates online and social sharing. 

SEO Best Practices for URLs

With the subdomain vs. subfolder decision out of the way, let’s talk about how to structure the URL path.
There are some documented best practices to make URLs friendly to search engines and users. It’s fair to say that it’s hard to follow every single recommendation, and that’s fine. Keep in mind that the goal is to keep URLs as simple and intelligible as possible

  • Use the target keyword. Although it’s a minor ranking factor, keywords in the URL are still important for search engines and meaningful for users. 
  • Make URLs descriptive and meaningful
  • Shorten the URLs, when possible. Be concise and avoid superfluous words without sacrificing readability. Although URL length is not a ranking factor, Google recommends URLs shorter than 2,000 characters. It’s also a good idea to keep URLs within 74 characters so they don’t get truncated in search results. 
  • Mirror the site structure, when possible. Using hierarchically organized folders in URLs isn’t too important for Google. However, using a URL structure that reflects the structure of the site content can make it easier for users to know where they are. Still, this is one of the cases where you need to use your best judgment because too many folders can make URLs unnecessarily complex and long. 
  • Be consistent. Be coherent in the use of https/http, www/non-www, trailing slash, and capitalization in URLs. The inconsistent use of those URL fragments can lead to duplicate content and a waste of crawl resources. This can become especially problematic if pages lack self-referring canonicals.
  • Use the same language as the page content. This can offer search engines and users an additional hint about the target language of the page. Keep in mind that it’s just fine to use non-Latin characters and accents in the URL. 
  • Include the language/region codes, if applicable. If your site is targeting multiple languages or regions, use the language/region codes in the URL since it can help search engines know what is the target audience of pages. 
  • Use hyphens. Google recommends using hyphens (-) instead of underscores (_) in URLs. 
  • Avoid the overuse of parameters, when possible. Parameters, those extra elements in the URL distinguishable by the question mark (?) and equal sign (=), can cause problems for crawlers. This is especially true if there are multiple URLs with parameters containing the same content. In large websites, such as airline websites, the excessive use of parameters in URLs can make Google consume much more bandwidth than necessary to crawl the website. This can lead to crawling and indexing issues. 
  • Avoid session IDs in URLs. Like parameters, session IDs in URLs can become very problematic for crawlers. Consider using cookies instead. 

What is the Best URL Structure for airTRFX Pages?

By default, any chosen URL structure in airTRFX already follows several of the best practices explained above:

  • They include the target keyword.
  • They are descriptive and meaningful. 
  • They are short enough without sacrificing readability.
  • They are consistent.
  • They use hyphens instead of underscores. 
  • They mirror the language of the page content.
  • They include the relevant language/region codes.
  • They exclude unnecessary parameters and session IDs. 

Below are the most SEO-friendly URL structures for airTRFX pages based on our experience and expertise. 

On gTLD, subfolder implementation

The subfolder implementation of airTRFX on Generic Top-level Domains (gTLD) offers the best option from an SEO standpoint. It would look like this:

  • Homepage: https://www.airline.com/en-us/flights
  • Flights to City: https://www.airline.com/en-us/flights-to-city
  • Flights from City: https://www.airline.com/en-us/flights-from-city
  • Flights from City to City: https://www.airline.com/en-us/flights-from-city-to-city
  • Flights to Country: https://www.airline.com/en-us/flights-to-country
  • Flights from Country: https://www.airline.com/en-us/flights-from-country
  • Flights from City to Country: https://www.airline.com/en-us/flights-from-city-to-country


  • Follows best practices.
  • Comes with the added benefits of a subfolder implementation. 


  • In some cases, tracking in Google Analytics and Google Search Console could be challenging.

On gTLD, subdomain implementation

airTRFX pages can be also hosted on a subdomain, and this is the best URL structure. 

  • Homepage: https://flights.airline.com/en-us/
  • Flights to City: https://flights.airline.com/en-us/flights-to-city
  • Flights from City: https://flights.airline.com/en-us/flights-from-city
  • Flights from City to City: https://flights.airline.com/en-us/flights-from-city-to-city
  • Flights to Country: https://flights.airline.com/en-us/flights-to-country
  • Flights from Country: https://flights.airline.com/en-us/flights-from-country
  • Flights from City to Country: https://flights.airline.com/en-us/flights-from-city-to-country


  • Follow best practices.
  • It is easier to track in Google Analytics and Google Search Console.


  • Comes with the downsides of a subdomain implementation.

On ccTLD

airTRFX also offers URL alternatives for implementations on Country Code Top-level Domains (ccTLDs). Below it’s the best option.

  • Homepage: https://www.airline.us/en/flights
  • Flights to City: https://www.airline.us/en/flights-to-city
  • Flights from City: https://www.airline.us/en/flights-from-city
  • Flights from City to City: https://www.airline.us/en/flights-from-city-to-city
  • Flights to Country: https://www.airline.us/en/flights-to-country
  • Flights from Country: https://www.airline.us/en/flights-from-country
  • Flights from City to Country: https://www.airline.us/en/flights-from-city-to-country


  • Follow best practices.
  • Comes with the added benefits of a subfolder implementation.


  • In some cases, tracking in Google Analytics and Google Search Console could be challenging.

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