Im doing a project and I would like to now if is a good practice use this type button
Someone can tell me?
Now, see this page in html, css + Js:
To get back to the raw question: I think there are fields of application for this kind of button. (As mentioned by others it should have another design - color, border, icons etc. )
In general this type of button design is used with forms and multicolumn configurators. The width of the button clarifies that all of the fields above are processed by this button.
In your case this seems to be correct. The small grey button for example processes only the field beside it.
It's not about the size, it's about the width. In this case.
No, it is not a good practice. Users will need more time than usually to understand that this is a button. Some will not be sure where should they click - on any place in the button or rather on the text.
I think Steve Jones has offered your first bit of feedback about the button - It's so large that it's become part of the background - A bit like how you can't see Europe while you're standing in the middle of Paris.
You also have a muddle of CTA colours: I can see yellow links, a grey button, what looks like a blue button, and then your large green button.
Pick one primary and one secondary CTA colour and stick to that palette - if you do that then your user will become conditioned to understand that items in those colours should be clicked - this, in turn, will reduce the size your button needs to be in order to be seen and clicked by the user.
Summary: The button doesn't need to be huge but it does need to be clearly visible and have some relationship with what ever it sends/activates/etc