HAR Files

In this article, I’ll talk and explain about HAR Files, so if you don’t know what they are, or, what do we use them for, you’ve come to the right place.


What are HAR Files? HAR, which stands for HTTP Archive format, is a JSON-formatted archive file format used for the logging of a web browser’s interaction with a certain site.

Basically, this file “records” and being used to track the activity and information being exchanged between the web browser and a website.

The common extension for these files is .har.

What do HAR files contain ?

  • Stalled/blocking : The time the request was pending before it was actually sent. This includes any time spent in proxy negotiations or when waiting for an established connection to become available for reuse.
  • DNS : The time spent performing the DNS lookup.
  • SSL : The time spent completing an SSL “handshake”.
  • Content Downloading period : The time spent receiving the data found in the response, as we know, you need to “download” a file before you can display it as a whole.
  • Waiting Period : The time spent waiting for the initial response.
  • Request Sending : The time spent issuing the network’s request.

An HAR file contains a lot of valuable information for determining where and how you can improve the website’s performance.

With the ability to view HAR data directly from the browser, it is quite easy to access and download the files containing this information. Additionally, in the case that you need to send a HAR file to someone for analysis, like Web Application Vulnerability Scanners for example!

Here, you can learn how to Export and Use HAR files in Kayran’s Web Application Vulnerability Scanner!

Stay safe, choose Kayran.