What are clean URLs --- What makes a URL clean?

Question

There is this terminology of "clean"/"short"/pretty" URLs.

What makes a URL this way?

• Is it the lack of a Cname value such as www.?
• Is it the lack of query string variables and their values?
• Is it the lack of both?
• Is it the lack of something totally different?

Answer 1

The Cname www if it is set to be part of the base URL is OK. It depends if the website uses www or non www. But it should be consistent to avoid duplicate contents. So it would still be a clean URL with or without. Consistency is a must for SEO point of view.

Yes clean url should not contain query strings and extensions like .html, .php, etc. I remember configuring clean URL for one site before and my boss wants to remove the .html extensions.

Query strings are dynamic hence the content of page may change depending on the query. This is usual on ecommerce sites where searching of products is a vital function.

Also, it should not contain program extensions like .html , .asp , .php

Examples of clean url would be:

• https://www.example.com
• https://www.example.com/cars
• https://www.example.com/cars/sports-car

Answer 2

There is no set definition or standard. Clean/Pretty is a concept to say that the URL should not have unnecessary and hard to read parts. My interpretation is that it should not be 'dirtied' by extra data or details irrelevant to visitors. The CNAME can be part of the domain and does not necessarily make URLs not clean but it should be predictable.

Generally query strings are not considered clean because they are hard to read. File extensions are not usually relevant to visitors, since they don't need to know if your side is HTML, PHP, JSP, etc. To me a clean URL only contains parts that are relevant to the user and allow the URL to be understood. This is a bit generic, so here are some examples:

• https://www.example.com [CLEAN]

• https://example.com [CLEAN]

• https://blog.example.com [CLEAN]

• https://en.example.com [CLEAN] (CNAME understood to be language of the site)

• https://server12345.example.com [DIRTY]

• https://www.example.com/index.php [NOT SO CLEAN]

• https://www.example.com/gadgets [CLEAN]

• https://www.example.com/gadgets.php [NOT SO CLEAN]

• https://www.example.com/product?type=gadgets [NOT CLEAN]

• https://www.example.com/gadgets/blue [CLEAN]

• https://www.example.com/?gadgets=blue [DIRTY]

• https://www.example.com/gadgets_blue [CLEAN]

• https://www.example.com/123456-gadgets_blue [DIRTY]

Answer 3

I am not sure there are any written standards on some of these but my understanding of their general use -

A clean URL is a URL which does not have a ? or & or tracking data embedded in it - ie it is just an address without any variables inficative of user tracking or user preference in it.

A short URL is a URL which uses as few letters as practical making it easy to communicate over twitter or SMS etc. Generally this is expanded to a more complex URL by some kind of mapping. Very often there is obfusication of the destination, and use of third party services is common.

A pretty URL is one where parameters/selections are embedded into the URL in such a way that they are fairly readable and does not include ? or & - A clean URL and pretty URL could be the same but a pretty URaL might include pregernces/hints to preferences which may not be present in a clean URL.