We're calling on all EU-based Mozillians with iOS or iPadOS devices to help us monitor Apple’s new browser choice screens. Join the effort to hold Big Tech to account!

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

Why Does Firefox Have a Launch Delay When I Set My Firewall to Block All Internet Traffic But HTTP?

  • 2 replies
  • 3 have this problem
  • 2 views
  • Last reply by BeKind

more options

If I set my firewall to block all traffic but HTTP/HTTPS then proceed to launch Firefox, Firefox will delay ten to fifteen seconds before launching. In my experience with other programs, such a delay usually means the software is trying to connect to a server somewhere and is timing out once it determines that it cannot connect. I guessed that perhaps it might be Firefox searching for updates or reporting data (telemetry, health & crash data) but I disabled the update check and the data-reporting and the delay is still present. What is likely causing this delay?


Windows XP Firefox 35.0 Delay occurs even when using a clean profile (default settings and no plugins installed).

If I set my firewall to block all traffic but HTTP/HTTPS then proceed to launch Firefox, Firefox will delay ten to fifteen seconds before launching. In my experience with other programs, such a delay usually means the software is trying to connect to a server somewhere and is timing out once it determines that it cannot connect. I guessed that perhaps it might be Firefox searching for updates or reporting data (telemetry, health & crash data) but I disabled the update check and the data-reporting and the delay is still present. What is likely causing this delay? Windows XP Firefox 35.0 Delay occurs even when using a clean profile (default settings and no plugins installed).

All Replies (2)

more options

hi, maybe the following article can give you some more clues: How to stop Firefox from making automatic connections

more options

philipp said

hi, maybe the following article can give you some more clues: How to stop Firefox from making automatic connections

Thanks for the link but I tried everything on the page and the delay is still present. Also, the delay is a bit longer than I thought. It's usually 20 seconds.