jQuery ロードしていないページでもChrome Consoleで $ が使える

Console Utilities API Reference  |  Chrome DevTools  |  Google Developers

$(selector, [startNode]) $(selector) returns the reference to the first DOM element with the specified CSS selector. When called with one argument, this function is an alias for the document.querySelector() function.

\((selector, [startNode])\)(selector) returns an array of elements that match the given CSS selector. This command is equivalent to calling document.querySelectorAll().

他にもいっぱい便利なAPIがあるので覚えておきたいですね。