Are websites hackable?

Question

So as the title you can see that my question is the same--
"Are websites hackable? If so is it possible even someone uses simple HTML,CSS and JavaScript? Also how to prevent it from happening?"

Answer 1

can be safe, just give a proper rules, handle every exceptions. (including variables, visibility)
if you have form, use the method post, but validate all data both in frontend and backend, etc

Answer 2

Hello my friend!, yes websites are hackable, Every day in France, websites even with top notch security get hacked by individuals.

It is very possible to use html css and js to "hack" a website and based on my little exp, this is commonly done in a term called "phishing".

You have your official website but someone comes and write every single line of html css and js that makes up your website and he pushes it live for all to see! This is misleading because some people unaware! will think the attackers website is the original and boom, there's the hack in this sense. So with this logic, you can find a way to prevent it from happening.

:)