View Source
One fascinating aspect of the web is that everyone must share code to participate. You send a request to a server, they send back some code. Your browser is not a black box–you can always peek under the hood!
Right click on any web page and select “View page source” to see the code that is being rendered by the browser (shortcut: Ctrl + U).
Or put view-source: in front of any URL in your address bar, for example:
view-source:https://evanwill.github.io/web-crash-course/
This is HTML!
Tip: some web pages override your right-click context menu with options specific to the page. You can override their override by holding Shift!