For a quick look without a second device there is eruda[1], which enables an inspector via a JavaScript call[2].
[0] https://developer.apple.com/library/archive/documentation/Ap...
[1] https://github.com/liriliri/eruda
[2] javascript:(function () { var script = document.createElement('script'); script.src="https://cdn.jsdelivr.net/npm/eruda"; document.body.append(script); script.onload = function () { eruda.init(); } })();
As someone who fondly remembers the early Firebug days, it is great to see this. It is very frustrating to me that tablets and phones are so powerful, but we can't do even basic dev stuff on them.
EDIT: Discussion 4 months ago https://news.ycombinator.com/item?id=22968079 , where nxrabl shared the tip of editing an existing bookmark with the javascript code to get it to work in Safari on iOS.
https://developers.google.com/web/tools/chrome-devtools/remo...
You can also load Eruda with Javascript. https://github.com/liriliri/eruda