How to distinguish a high-quality website code from a low-quality one?

Project managers and developers reiterate how important code quality is. But how can you know if your code is well written?
We have formulated several points that will help you quickly and easily assess how well the project is completed:
Well-developed code structure.
The structure of the site should be designed in such a way that if you remove any section of the site, the rest of the page will not be broken.
The site is equally well displayed on all browsers and devices (computers, laptops, mobile phones).
Old versions of Internet Explorer are an exception.

Site speed.
Site speed can be checked using the service: Google Pagespeed
It is desirable that the site is in the green zone. If the site has a lot of animations, videos or complex functionality, it is also permissible for a site to be in the yellow zone.

Errors in the code.
The existence of errors in the code can be checked using the service: https://validator.w3.org/
It is allowed to detect 3-5 errors (red lines) and any number of warnings (yellow lines).
If there are a lot of red lines, then this indicates poorly written code.

Is the site ready for promotion?
This service: https://sitechecker.pro/ Will help you determine if the site is ready for promotion in search engines.

It is better to check each page of the site before starting the promotion.
The ability to change the content through the admin panel.
All site content must be located in the admin panel. The only exception can be short labels, for example, labels on buttons.

The quality of the images should be high enough.
High quality image Low quality image
Do you want to know more? Check the next post: How to distinguish a high-quality design from a low-quality one?