IE11 performance profiler not giving any results

Question

I'm trying to improve my site's performance in IE11 and I cannot seem to get any results out of the performance profiler. I've read this page and it seems pretty straightforward but I must be missing something. Here are the steps I take:

1. On the F12 tools Performance tab, I click on either the green play button or the "Start profiling to begin a performance session (Ctrl+E)" link.
2. I perform an action in my app (as simple as clicking on a field and back out)
3. I hit the red stop button or the Stop profiling to generate a report (Ctrl+E) link
4. The Profiler tab shows "Analysing the collected data:" with an empty progress bar. The progress bar never goes anywhere and after a few seconds the Profiler tab just reverts to saying "Start profiling to begin a performance session (Ctrl+E)".

This happens on any website that I try, not just mine. The rest of the F12 tabs (DOM, Console, Network) all work fine. Using IE version 11.125.16299.0, update version 11.0.49 on Windows 10.0.16299.

What am I doing wrong?

Answer 1

I don't think you're doing anything wrong. The performance profiler appears to be unable to show the reports it generates in IE11 right now. However, the fact that IE and Edge seem to share their debugging tools (in Windows 10 at least) might offer a viable workaround.

1. Press CTRL-E, perform your actions, press CTRL-E again, and wait for the performance tab to revert to its initial state. Some part of the profiler seems to have crashed at this point; you'll find that the "import" and "export" buttons won't work.

2. Exit the debugging tools, open them again, and open the performance tab.

3. Click on the (now operational) "export" button to save your profiler report.

4. Open Edge, start its debugging tools, and go to the performance tab.

5. Import your saved profiler report. It'll show up just fine now.

For what it's worth, importing your saved report into the IE11 debugging tools will result in an error about "Promise" being undefined or somesuch. This makes sense, as the ES6 Promise constructor is supported by Edge but not by IE11.