Does Firefox ignore the hosts file? How to make Firefox honor the hosts file

firefox hosts

17,132

Solution 1

I had the same problem. Write about:config in the address bar.

Search for dns and change network.dns.offline-local to false.

Solution 2

I fixed it by disabling the "DNS Over HTTPS" Firefox Network option.

Solution 3

If the domain that is not working either in Firefox or Chrome ends as following:

.dev
.localhost
.test
.example
.app

The problem is that, both browsers in certain distributions don't like domain ending like that, in my case changing the domains from *.localhost to *.local solved the issue.

As I mention in a comment in this post where I found the solution, it happens in certain distributions, eg. I don't have this issue in my Ubuntu 20.04 installation, but I got the error in Xubuntu 20.04 (both browsers).

17,132

user9371654

Updated on September 18, 2022

Comments

user9371654 almost 2 years

I'm using Firefox browser in Ubuntu 18.04. I made an experiment where I want some domain names to be resolved to another IP address than their actual one. Firefox seems to ignore the IP in the hosts file.

1) Is this expected behavior from Firefox?

2) If yes, how to make Firefox honor the hosts file?

3) If not possible, are there alternative browsers that honor the hosts file?

I use Linux Ubuntu 18.04
- Zeitounator about 5 years
  
  I use the hosts file to direct well known adds sites to 127.0.0.1 as a cheap add-blocker and it works very well. So the answer is no, firefox (as all other browser I've tried) honors /etc/hosts. You should double check your hosts file content.
- DrMoishe Pippik about 5 years
  
  Windows 10 itself will ignore hosts, e.g. when used to block telemetry. See petri.com/…
- LMiller7 about 5 years
  
  I don't know much about Linux but in Windows browsers don't consult the hosts file. That is done at a lower level in the system and the browser has no choice whether it is used or not. I suspect a problem in the hosts file.
- user1686 about 5 years
  
  The browser (on PC operating systems) always has a choice to not use the system-provided mechanisms in the first place. It can send its own UDP packets or make TCP connections.
- Eddie over 3 years
  
  ipv6 was the problem for me. Solution here: superuser.com/a/753863/77247
Nick Woodhams almost 5 years

After switching this, I just needed to close Firefox entirely and reopen and it started to honor the hosts file. Thanks.
RockPaperLz- Mask it or Casket over 4 years

On what operating system did you run your tests?
Universal4 over 4 years

Windows 10 Firefox 71.0 As I stated I have used the hosts file for MANY years for many reasons such as test sites of live domains in a different ip, or servers on my lan etc. the recent few revisions of firefox made some sort of change the last year or so that just seems to drive me into brick walls ina number of places that may force me to change but I would rather conquer the underlying reasons and continue to use my preferred browser
Gary - Stand with Ukraine about 4 years

+1. By design, DNS Over HTTPS ignores hosts files. See bugzilla.mozilla.org/show_bug.cgi?id=1453207#c2
Alex about 4 years

This was my answer too! Thank you @Erpallo. I tried everything and you saved the day!
michael about 4 years

😲 omg, TIL (btw: wtf?!)
Lubo Kanev over 3 years

Firefox still ignores the hosts file after following this and the other answers, even after restart. I noticed if I create a new Firefox profile, it works there.
Nickolay over 2 years

Firefox 83+ honors /etc/hosts with the default settings, but you do need to restart after making changes to the hosts file.