Stop “detectportal.firefox.com” from proxy tools Burp & Fiddler

How to stop Firefox from spamming your proxy tools like Burp/Fiddler with “detectportal.firefox.com”

Yuthan Balaji K
3 min readJun 18, 2022

As a researcher/developer/cyber professional/any person, when you are working on HTTP requests of an application using Mozilla Firefox, you should have come across the host “detectportal.firefox.com” spamming your proxy history, as shown below.

This is very annoying as it makes us difficult to track the HTTP requests of the application we are working on as well as it will consume a lot of memory as it gets triggered for seconds.

If you have experienced the same, and you are seeking an answer, yeah, you’re in the right place, mate!

My experience & gratitude ❤️

As an ethical hacker, I used to work with proxy tools every day. Firefox is my go-to browser as it is convenient with multiple free extensions, custom extensions and without any organisation rules! 😉
However, Firefox spams my proxy tools with “detectportal.firefox.com”, which was annoying most of the time.

Thanks to my mate Jamie, he introduced me to this solution, which helped me get rid of “detectportal.firefox.com” permanently.

After benefitting from it, I thought of giving a shoutout which may help someone perplexed like me.

Let’s crack it down.

It’s not a tedious job, mate. Just a 3 steps process.

Step 1: Visit Config page.
Open a new tab in Firefox and visit “about:config” page.

Accept the risk and continue.

Step 2: Search for the keyword.
Type “Captive” in the search box and wait for it to load the list matching the keyword.

Step 3: Disable the control.
Look for the control named “network.captive-portal-service.enabled”.

If it has the value as “true”, then double-click on the value “true” or click the toggle button towards the right of the control to change the value to “false”.

The result should look like “network.captive-portal-service.enabled false”.

Good job, mate. You have done it. 👏 😄

Now go ahead and continue your work with the tool. You won’t see the host any more apart from the history, or if you accidentally enable it again. 😉

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Yuthan Balaji K

Cyber Security Professional | Pentester | Automations & Innovations key player