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

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

# Fiddler HAR record

Fiddler is a free web-proxy which allows to capture HTTP and HTTPS requests and responses. Fiddler is very simple to use once configured. It allows to record HTTP scenarios within minutes.

## Installation

[Download Fiddler](http://www.telerik.com/download/fiddler) and install Fiddler. Then, launch Fiddler. It should configure the HTTP proxy automatically on your browser and starts recording HTTP requests.

!!! Info
    In case you have issues with the following procedure, you can download our <a href="https://api.octoperf.com/doc/design/create-virtual-user/har-recorder/img/fiddler/fiddler.har" download>sample HAR file</a>.

## HTTPS Configuration

Fiddler needs to be set up properly in order to record HTTPS Traffic:

* Click on *Tools > Preferences...*, a dialog should be displayed,
* Select *HTTPS* tab in the preferences dialog,
* Check *Capture HTTPS CONNECTs* and *Decrypt HTTPS Traffic*,
* [Export and Trust Fiddler Root Certificate](http://docs.telerik.com/fiddler/Configure-Fiddler/Tasks/TrustFiddlerRootCert).

![Fiddler HTTPS Preferences](https://api.octoperf.com/doc/design/create-virtual-user/har-recorder/img/fiddler/fiddler-https.png "Fiddler configured to decrypt HTTPS Traffic")

## Response Bodies Configuration

**This is an important step**. *Variable Extractors* and *Correlation Rules* are important features that require response bodies.

* In the bottom left text field dedicated to *command-line*, put **prefs set fiddler.importexport.HTTPArchiveJSON.MaxTextBodyLength 10000000**
* Press *Enter*. 

This configures *Fiddler* to save response bodies up to 10.000.000 bytes.

![Fiddler Preferences](https://api.octoperf.com/doc/design/create-virtual-user/har-recorder/img/fiddler/fiddler-prefs-response-body.png "Fiddler Text response body max length")

*Sets the text response body max length to 10.000.000 bytes*

## Hide HTTPS Connects

To avoid any "noise" in your recording, it is also recommended to hide the HTTPS connects.
This way only HTTP/S requests will be exported from fiddler:

![Hide connects](https://api.octoperf.com/doc/design/create-virtual-user/har-recorder/img/fiddler/hide-connects.png "Hide HTTPS connects")

## Recording the scenario

Record your scenario by browsing with your favorite web-browser. The requests and responses should appear in fiddler. Once finished, export your recorded fiddler sessions. Remove any unwanted request from the list before saving it. Now, it's time to export the recording as HAR.

![Fiddler Recording](https://api.octoperf.com/doc/design/create-virtual-user/har-recorder/img/fiddler/fiddler-recording.png "Example of a fiddler recording next to the browser window")

## Saving the recording

![Fiddler Export Sessions](https://api.octoperf.com/doc/design/create-virtual-user/har-recorder/img/fiddler/export-fiddler-sessions.png "Export All sessions as HAR")

Click on _File > Export Sessions > All sessions..._ in the top menu. A dialog should ask you the preferred export format.

![Fiddler Export Format](https://api.octoperf.com/doc/design/create-virtual-user/har-recorder/img/fiddler/fiddler-export-format.png "Fiddler Export Format Dialog")

Choose _HTTPArchive v1.2_ export format and click on _Next_. Save the file on your disk.

![Fiddler Save File](https://api.octoperf.com/doc/design/create-virtual-user/har-recorder/img/fiddler/fiddler-save-har.png "Save the HAR File on your hard disk drive.")

## Create Virtual User: Import HAR

Great, we're just one step behind having a virtual user created from a Fiddler recording. Import the previously saved HAR file on OctoPerf.

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

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

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.