Windows 10 reached EOS (end of support) on October 14, 2025. If you are on Windows 10, see this article.

Avatar for Username

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More
Open

Firefox constantly sending data 3KByte/S to Cloudflare servers

Firefox Privacidade e seguranza
jbr replied
GT2026-XYZ
GT2026-XYZ

I have recently discovered that Firefox is constantly sending data at around 3KBytes/S to a variety of Cloudflare servers.

What is the data that is being sent and why is this happening?

This has started to occur in one of the last updates to Firefox.

Currently running 151.0.4 (64-bit) on Windows

Does this constitute a privacy violation, what is the data that is being sent?

I have recently discovered that Firefox is constantly sending data at around 3KBytes/S to a variety of Cloudflare servers. What is the data that is being sent and why is this happening? This has started to occur in one of the last updates to Firefox. Currently running 151.0.4 (64-bit) on Windows Does this constitute a privacy violation, what is the data that is being sent?

All Replies (1)

jbr
jbr
  • Top 10 Contributor

And you don't have Cloudflare set for Firefox DNS over HTTPS as the provider? (It should not be requesting things constantly even when idle but there's enough internal service endpoints to hit even in background to generate DNS traffic however I'd expect for the same hosts this to be reasonably cached to start with.)

If you create a new clean profile without addons and no tabs/sessions to restore, do you still see it?

Generally most of Mozilla traffic terminates at Fastly POPs, incl. OHTTP and IP protection features.

Ask a question

You must log in to your account to reply to posts. Please start a new question, if you do not have an account yet.