How to disable Firefox DNS Cache?

firefox, firefox browserFirefox cached DNS entries. You cant clear firefox dns cache but you can disable firefox dns cache. There are 2 ways of disable firefox dns cache.

1st method to disable firefox dns cache is to install the DNS cache plugin.


  • Download and install DNS Cache add on for firefox
  • Right click on your “Home” button at Firefox and click on “Customize”
  • Look for the “DNS Cache” button and drag it beside your “Home” button, and click “Done”
  • Now your Firefox has “DNS Cache” button beside the “Home” button.
  • Whenever you want to disable the firefox DNS cache, just click the “DNS Cache” button.

2nd way to disable firefox cache is thru manual editing.

  • Start your Firefox, enter “about:config” at the location bar and press enter. If you are using Firefox 3 then u’ll see a warning page, just click “I’ll be careful, i promise” button.
  • U’ll see a lot of record, just right click at the blank place and select “New” -> “Integer”
  • Enter “network.dnsCacheExpiration” as the preference name and “0” as the integer value
  • Right click and select “New” -> “Integer” again
  • This time enter “network.dnsCacheEntries” as preference name and “0” as integer value
  • Done, you just disable the firefox dns cache

Happy browsing.

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5 Responses to “How to disable Firefox DNS Cache?”

  1. Asad Kamran says:

    Although i don’t try the above solution, but a almost similar Firefox solution not work for me, and came to this solution. worked perfectly for me.

    Run this on command prompt:

    ipconfig /flushdns
    net stop dnscache
    net start dnscache

    after executing first 2 lines , issue in FF resolved and site page loaded accurately.

  2. Jan says:

    Hi, Thanks for this tip. This a must for web developers!

  3. Brad says:

    You can clear the cache I just did it by Tools > Clear Browsing History.

    Untick everything except cache. But I think this will mean websites will re-download stuff again.

  4. Dan says:


    The about:config fix was so simple, but it doesn’t seem to work. Running 3.6.8 on Linux/x86 (Gentoo) and even after a restart of firefox it’s still caching old entries from /etc/hosts even though I can no longer ping them. Perhaps I did something wrong, although the process was pretty straightforward.

    Incidentally, to get out my frustration, I want to say that I hate the fact that firefox caches DNS entries. I don’t think it used to, and now that it does it causes me a headache every day. Why does a browser need to cache DNS anyway? The vast majority of people already have a DNS cache on their computer.

  5. Poobs says:

    Hey, works great! I managed to flush my DNS cache no problem with this, but do you know how to remove the key after I’ve used it? I’d rather not give it a value so my cache doesn’t flush, but all I could do is reset to string :/

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