JMeter: How to Turn Off Captive Portal from the Recording Using Firefox

Apache JMeter is an Apache project that can be used as a load testing tool for analyzing and measuring the performance of a variety of services, with a focus on web applications.

Assume you have installed JMeter and are familiar with it; otherwise, you can watch a good series of videos here to get started.  In this article, we will discuss how to remove the extra HTTP request (1 /success.txt ) in the recording (click below diagram to enlarge).

HTTP(S) Test Script Recorder

You can follow the instructions here to record your web test with "HTTP(S) Test Script Recorder".  In this article, we have chosen Firefox as the browser for JMeter's proxy recorder.

When we recorded a test plan, some repetitive HTTP requests related to Captive Portal feature in Firefox

GET http://detectportal.firefox.com/success.txt

have been captured.  These HTTP traffics are not related to the tested web application and should be excluded from the test plan.  So, how can we achieve that?

How to Turn Off "Captive Portal"

Captive Portal feature in Firefox covers the detection and implementation of handles for captive portals inside Firefox browser. Firefox is expected to handle the handling of a captive portal page upon detection of such.

There is no UI checkbox for disabling Captive Portal.  But, you can turn off Captive Portal using the Configuration Editor of Firefox:^[3]

1. In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful.
2. In the search box above the list, type or paste captiv and pause while the list is filtered
3. Double-click the network.captive-portal-service.enabled preference to switch the value from true to false

If you are in a managed environment using an autoconfig file, for example, you could use this to switch the default:

user_pref("network.captive-portal-service.enabled", false)

References

1. Apache JMeter
2. JMeter Beginner Tutorial 21 - How to use Test Script Recorder
3. HTTP(S) Test Script Recorder 
4. Proxy Step by Step (Apache JMeter)
5. Book: Apache JMeter (Publisher: Packt Publishing) 
6. Turn off captive portal (Mozilla Support)
7. JMeter—Use Extractors (Post-Processor Elements) for Correlation (Xml and More)