When a website decides to expand into new languages or markets, one of the first and most important decisions is the URL structure it will use.
In international SEO, site architecture matters because search engines need to understand which version of the content should be shown to each user based on language or country. Google’s current guidance is still clear on the fundamentals: use different URLs for different language versions, and use hreflang annotations to help search engines connect equivalent regional or language variants.
A poor international setup can create crawling, indexing, and targeting problems. This becomes especially important when content is very similar across countries, such as Spanish for Spain and Spanish for Argentina, or English for the US and the UK. Google does not treat properly localized pages as duplicates just because they are similar, but it does help to make those relationships explicit through the right URL structure and hreflang implementation.
This is even more important in e-commerce. Search engines should be able to surface the right version of the site for each market so users land on pages with the correct language, currency, shipping information, and commercial details.
There are four common ways to structure an international website. Each has advantages and trade-offs, so the right choice depends on the needs, resources, and long-term goals of the project.
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Subdomains
Subdomains are one option for serving international content. A subdomain is part of the main domain, but search engines can still treat it as a separate entity of the site.
An example would be mx.example.com.
One of the main advantages of subdomains is flexibility. They can be useful when different markets need partial technical independence, separate CMS setups, or a different hosting and deployment structure.
They can also make regional targeting clearer from an organizational point of view, since each market sits in its own isolated section.
The main drawback is that subdomains do not usually consolidate authority as efficiently as subdirectories. From an SEO perspective, they often behave more like separate properties than like a single unified site, which can make growth slower if authority is split across multiple versions. That is one of the reasons why subdirectories are often preferred when the business can support them operationally.
Subdirectories
Subdirectories are folders under the main domain. An example would be example.com/mx/.
This is usually the simplest and most efficient option for many international websites. All versions remain under the same domain, which tends to make maintenance easier and helps consolidate authority more naturally across the site.
Subdirectories are also easier to manage when all markets share the same infrastructure, the same CMS, and similar technical requirements. For many brands, this is the most practical balance between SEO performance, scalability, and operational simplicity.
The downside is mostly related to perception and internal complexity. Users may not always notice the market or language version from the URL alone, especially on mobile devices where the full URL is rarely visible. They can also become harder to manage if each country requires very different functionality or technical customisation.
Separate domains or ccTLDs
Another option is to use separate country-code top-level domains, or ccTLDs.
An example would be example.mx.
This is the strongest signal for country targeting, because the domain itself already indicates the intended market. It can also inspire more trust in countries where users are used to local domains and expect to transact on them.
The main downside is cost and complexity. Each domain has to be managed separately, and that usually means more work in terms of SEO, infrastructure, tracking, governance, and link acquisition. You are effectively building several websites rather than one international site.
It is also important to remember that ccTLDs target countries, not languages. If you need to target multiple languages within the same country, you will still need an additional language structure inside that local domain. That is common in markets such as Belgium or Canada.
Using URL parameters to distinguish languages
It is technically possible to use URL parameters to separate language or regional versions, such as example.com/?location=mx.
However, this is usually not the best option for international SEO. Google recommends using separate URLs for each language version instead of relying on cookies, browser settings, or more fragile mechanisms.
The problem with parameters is not that they are impossible to crawl, but that they are usually less robust, less intuitive for users, and harder to manage cleanly at scale. They are also a weaker architectural signal than subdirectories, subdomains, or ccTLDs.
In practice, if a site is serious about international SEO, URL parameters are rarely the best long-term choice.
In short, the best international architecture depends on whether you are targeting languages, countries, or both, and on how much technical and operational complexity the project can support. Subdirectories are often the most efficient choice, subdomains can work well when markets need more independence, ccTLDs are the clearest country signal, and URL parameters are usually the weakest option for this kind of setup.
