What tools I can use to find out what JavaScript hangs the web-page if it occurs rarely?

Question

What tools I can use to find out what JavaScript hangs the web-page if it occurs rarely (which means it's very hard for me to reproduce it)?

I'm using Google Chrome browser in Windows. Is it possible to find out using browser's tools what hangs the page? "Developer tools" menu option opens blank panel.

PS. Offending web-site is "www.vk.com". Same issue was confirmed in Safari and Opera. So it's definitely not browser-specific problem.

Answer 1

You should have look at Windmill.