> OctoPerf load testing - FireFox HAR import documentation page. How to record an HAR file using FireFox and import it in OctoPerf?

Source: https://api.octoperf.com/doc/design/create-virtual-user/har-recorder/record-firefox-har/

# Firefox HAR record

Firefox has a built-in extensions which allows to easily record requests and responses and export them as HAR format.  

![firefox-record](https://api.octoperf.com/doc/design/create-virtual-user/har-recorder/img/firefox/firefox-record.gif)

*Quick Video explaining how to record HTTP requests with Firefox*

## How to record

The following procedure explains how to record HTTP as an HAR file with Firefox:

* Start Firefox,
* Then press _CTRL_ + _SHIFT_ + _P_ to start an incognito session,
* Press _CTRL_ + _SHIFT_ + _I_  to display the developer toolbar,
* Select _Toolbox options_ tab, and check enable persistent log,
* Go back to_Network_ tab
* Navigate to record HTTP traffic,
* Right-click on any request and select __Save All As HAR__.

!!! Info
    In case you do not have Firefox, you can download our <a href="https://api.octoperf.com/doc/design/create-virtual-user/har-recorder/img/firefox/firefox.har" download>sample HAR file</a>.

## Create Virtual User: Import HAR

Upload the newly created _HAR_ file to create a virtual user: 

![Create Virtual User from HAR](https://api.octoperf.com/doc/design/create-virtual-user/har-recorder/img/firefox/import-har-firefox.png "Create your virtual user from the recorded Firefox HAR file")

Simply drop the file in the HAR area or use the _Upload new HAR file_ button and hit _Next_.

!!! Warning
    **If a response/request is truncated by Firefox** follow this procedure:
    
    - Type **about:config** in the URL bar to open the configuration page
    - Increase the values of those parameters ("0" or "-1" won't configure them as unlimited) :
      `devtools.netmonitor.requestBodyLimit`
      `devtools.netmonitor.responseBodyLimit`

Before uploading, you can adjust the [import options](https://api.octoperf.com/doc/design/create-virtual-user/har-recorder/#import-options): ad blocker, static resources and think times.