Here are keywords that you can’t use in JavaScript for variable names and identifiers:

await, break, case, catch, class, const, continue, debugger, default, delete, do, else, enum, export, extends, false, finally, for, function, if, implements, import, in, instanceof, interface, new, null, package, private, protected, public, return, super, switch, this, throw, true, try, typeof, var, void, while, with, yield

You should also avoid these HTML event handlers as identifiers:

onblur, onclick, onerror, onfocus, onkeydown, onkeypress, onkeyup, onmouseover, onload, onmouseup, onmousedown, onsubmit