Understanding URLs

By Martin Edwards

Published January 2018

You might not know it’s called a URL, but this is what one looks like:


A uniform resource locator (URL) identifies a particular website on the Internet, or a particular page or feature within a site. Knowing how to interpret a URL is an important life skill, because it’s arguably the best way to tell whether a website is genuine or bogus. There are two parts that matter.

Part 1: the scheme

The first part (called the scheme) is always https or http, followed by a colon and two slashes. Some browsers hide this part, but a padlock next to the URL indicates https.

Note: https alone does not mean you’re on a genuine website. A bogus site might also use https. It’s no consolation knowing your message is safe from eavesdropping if the party at the other end isn’t who you think it is!

Part 2: the domain name

This is the important bit. The domain name continues until either a slash or the end of the URL, whichever comes first. In the earlier example, it’s en.wikipedia.org.

Computers actually read domain names from right to left, separating them at the dots. Usually, the rightmost part – or two – indicates a country and/or type of organisation:

These are called top-level domains. The part immediately to the left of the top-level domain is typically the name of the organisation:

Note: There are exceptions, like diy.com which belongs to do-it-yourself retailer B&Q.

Combining these parts, we have full domain names:

These are the best indicator of the legitimacy of a site. Remember, what matters is the sections immediately before the first single slash (or end of the URL).

Bogus sites might be a misspelling of a genuine domain:

Using your knowledge

Now that you know how to interpret the two important parts of a URL, you can put this knowledge to use to protect you from scams, typically when you receive a suspicious email, or if a website you’re viewing doesn’t seem right.

Note: If you have a Mac and use Safari, this doesn’t happen as standard. To make it happen from now on, click View > Show Status Bar.


I wanted this guide to be really short, but it would be foolish of me to not explain a few common caveats that make interpreting URLs harder in some cases.

Complication 1: a genuine subdomain

Sometimes, you’ll see subdomains:


Is this the real Apple website? Yes! The rightmost part of the domain is apple.com. Apple just happens to be using a server called secure-applednld (for serving downloads).

Complication 2: a trick subdomain

On the other hand, a crafty bogus site might use a subdomain in this fashion:


Is this the real BBC website? No! At a glance, it looks like it might be an article in the Health section, but there’s no slash after bbc.co.uk — the domain name continues, in this case to the end of the address. It’s an elaborate one that in fact resolves to the server hosting this website, martinedwards.co.uk. If I was so inclined, I could create a page at this URL, mimicking the BBC but with some malware thrown in.

Complication 3: redirects

A domain name that looks suspicious at first might actually ‘redirect’ you to a genuine site. For example, if you’re on John Lewis’s mailing list, the emails you receive might contain links to promotions that look like this:


The domain list-manage.com is used by email marketing company MailChimp to track which subscribers click which links in an email. This data helps the owner of the mailing list (like John Lewis in this example) learn more about its customers, or simply how many people are interested in the promotions.

Complication 4: shorteners

Some people and companies use ‘shorteners’ to make URLs that are more compact or easier to communicate. These are really just redirects, but are increasingly common so deserve a special mention. For example:

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