Pretty-print a minified file
To prettify a minified file, click the Pretty print source icon at the bottom of the source pane. The debugger formats the source and displays it as a new file with a name like: “{ } [original-name]”.
After you click the icon, the source code looks like this:
The Pretty print source icon is available only if the source file is minified (i.e., not an original file), and is not already “prettified”.
Note
Currently Firefox does not support pretty printing inline Javascript.