Is there some programmatic way (or maybe a browser plugin) that allows users to arbitrarily run any jQuery they want on a webpage that is currently loaded in their browser?
Edit:
My motivation is to be able to test jQuery syntax and commands ahead of time on a page and then go add them to its source or suggest tweaks to the webadmins whose pages I experimented with.
I have been using jQuery from the main site to run the tests. It is currently on 3.5.1: jQuery download page
javascript:alert('hi');
into the address bar. To load jQuery, you can use the jQuerify Bookmarklet. What exactly are you trying to do (or prevent)? – Gradeigh