Chrome not showing OPTIONS requests in Network tab

Question

My web client application is setting HTTP POST requests via fetch API.

I see that OPTIONS preflight requests are sent via debugging proxy (Charles Proxy), but they

Answer 1

You'll need to go to: chrome://flags/#out-of-blink-cors, disable the flag, and restart Chrome.

This is an expected behavior change according to:
https://bugs.chromium.org/p/chromium/issues/detail?id=995740#c1

I originally came across this via:
https://support.google.com/chrome/thread/11089651?hl=en

Answer 2

Chrome 81 does not seem to display anything even after changing the option and restarting on my computer.

As an alternative solution, I started to use Firefox and its Network tab for development.

https://getfirefox.com

Answer 3

I'm Takashi from Chromium Project, and drove the Out-Of-Blink/Render CORS project.

The project intended to introduce a process isolated CORS implementation for better security and privacy, and many of new network related features rely on this new implementation. Unfortunately we temporarily disabled preflight support in DevTools as it turned out continuing to support it weakens security and privacy. Sorry for inconvenience during this period.

Good news is now Chrome 83 implements the CORS preflight DevTools support again in a security preserved way. So you can monitor the CORS preflight requests as you could do before the Out-Of-Blink/Renderer CORS.

Best,