Display the HAR format


We have seen the HAR (Http ARchive) format as the output from the BrowserMob proxy implementation and the NetExport implementation. The HAR file contains a log with requests and responses to the server. The file can be displayed as a waterfall or as an expandable tree. This recipe shows a couple of ways to view the HAR format.



Make sure you gathered a HAR file from the application under test.


We will see how to view a HAR file by using an online viewer.

  1. Open the online HAR viewer, http://www.softwareishard.com/har/viewer/
  2. Copy and paste the contents of the HAR file into the textbox. We can also drag and drop the file from our file-system to the website.
  3. Press Preview, in case you copied the contents of the HAR file.
  4. The result will look like the image below:

What has been done

The online HAR viewer reads the HAR file and builds the waterfall diagram.

There’s more…

There are more ways to view the HAR files. This section will cover a couple of frequently used ways.


We have to follow a couple of steps before we can view a HAR file in Fiddler. The steps are described below:

  1. Download fiddler from the following website: http://www.fiddler2.com
  2. Install Fiddler on your local machine
  3. Click on File → Import Sessions… and select your import format
  4. Select the existing HAR file from your filesystem.
  5. All the details from the sessions are visible in Fiddler.


NetExport gives us the functionality to upload the HAR file to http://www.showslow.com/beacon/har/. The HAR file is now accessible from the internet and can be easily shared with others. It is even possible to install ShowSlow on a private server to limit the risk.

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