How can I see HTTP headers triggered by web browers (Firefox, Chrome, Safari) in the exact same order they are built

Question

I need to know exactly in what order HTTP headers are sent from my browser (whatever it is - I tried Chrome, Firefox and Safri with the same results).

The intent is to build a scraper that will mimic not only the User Agent of these browsers but also the browser "fingerprint".

I can use Wireshark to see but it is not always quick to use. I would love to have this order available through a Dev Tool embeded in browser but headers are reorganized alphabetically.

See below HTTP headers as they are constructed by the browser (sniffed with Wireshark)

And then, what the Dev Tool from Firefox is telling me

Do you know an quick way to get this information? Is there an option to activate in Dev Tools preferences? An add-on already available?

Thank you for your time,

Answer 1

Actually, I find a little tip with Firefox.

By building a new query from the previously sent, with the Web Developper tool, Firefox is displaying headers as they were send over the wire.

Quite handy!

See below - headers are now displayed in their real order (not alphabetical one)