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

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$(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().