There is a special and pretty secret mode in browsers, called design mode.

When you set a page into design mode, you can edit the content of the page directly inside the browser page, which is very handy to test some prototype or check out how a new headline would look, for example.

How do you enable it? Open the DevTools console, and type:

document.designMode = 'on'

The same result can be triggered by enabling contentEditable on the body element, like this:

document.body.contentEditable = true

You can edit text, delete it, and also drag images around to reposition them.

You can turn off the mode by using

document.designMode = 'off'

This feature is supported by almost every browser, IE included. It’s pretty old, but quite unknown.

Lessons in this unit:

0:	Introduction
1:	Clipboard API
2:	Scrolling
3:	Console API
4:	Speech Synthesis API
5:	How to get the scroll position of an element in JavaScript
6:	▶︎ How to make a page editable in the browser
7:	Safari, warn before quitting