Set up a framework to fully man-in-the-middle my own browsers’ networking and see what they’re up to beyond just looking at their DNS queries and encrypted tcp packets. We force the browser to trust our mitmproxy cacert so we can peek inside cleartext traffic and made it conveniently reproducible and extensible.
It has containers for official Firefox, its Debian version, and some other FF derivatives that market a focus on privacy or security. Might add a few more of those or do the chromium family later - if you read the thing and want more then please let us know what you want to see under the lens in a future update!
Tests were run against a basic protocol for each of them and results are aggregated at the end of the post.
Posting with ambition that this can trigger some follow-ups sharing derived or similar things. Maybe someone could make a viral blog post by doing some deeper tests and making their results digestible ;)
Cross-post. Original Thread @ https://discuss.tchncs.de/post/53845514


It looks like Konform is a nice choice. Anyone tried it?
Daily-driving it now. I think it’s great. If you’re somewhat familiar with the landscape otherwise I think readme explains how it’s different and why. If you don’t mind losing out on some "safety"1 and latest upstream features2 for the sake of a more stable and predictable base, not having reliance on proprietary integrations or even internet, and really removing all non-essential network integrations, then definitely worth a try!
1: A surprising amount of people think (or at least write online) that a browser that doesn’t block user requests completely aligned with the Google SafeBrowsing blocklists is unsafe and that doing those syncs is an essential feature. If you think this is the only safe default option in 2026 I’m sorry but please consider uBlock Origin. See how opinions on who to trust can affect what “most secure” means. Konform Browser removes many assumptions of trust. But not all; Everyone still comes with an assumed PKI after all and there exists a default for DNS.
2: Since it’s ESR base it means new feature updates from Mozilla ~yearly instead of ~monthly. Still receiving security updates on the rapid schedule. No AI features out of the box.
Disclaimer: Am konform dev so shouldn’t be a surprise that it’s working well for ourselves I guess. Eager to hear to what extent it’s overfitted for our usage or really as great as I think it is ;)
BTW if you, dear reader, think queries in report of results are cherry-picked in a way that favors it (I don’t think they are but hey, fair), I’m also eagerly accepting input and especially PRs for queries (still have the raw dumps so I can add this quickly) or steps to test procedure (this means I have to rerun all of them so might take longer to update) that could illustrate different tradeoffs and show a more complete picture. Bring it on <3