Sharepoint Online Branding Master Page

Question

Hi I woud Like to change a little bit the theme of sharepoint. At the moment I know that isn't a good pratice to change the content of masterpage. However, If I want to make a Intranet with a bigger Header and add a Footer where should I edit/Create? Is is possible to do this with only HTML, CSS and JS?

Should I create a html file and than convert him to master page and add other componnents parts? (I'm new to sharepoint).

I'm using Sharepoint Designer to edit and see my files from our site.

Answer 1

You could add customization to header/footer by SPFx extension for modern view.

Custom SharePoint theming follow by json schema.

For classic view, you could inject custom JS by Add-PnPJavaScriptLink