HAR files are a major source of information when troubleshooting Web based issues. They provide useful information from all major browsers about HTTP request parameters, as well as status responses and payloads. A great example of what the various HAR file fields report is shown here, which includes the break down the various stages of a browser request to Web server, from the DNS request, to the TCP connection, SSL handshake to finally sending the request and getting the initial and full response
Here are the procedures to generate HAR files on the most common browser platforms, Chrome/Firefox and IE.
CHROME: | MS EDGE:
How does one actually view this information once it is exported from the browser?
All WSS access types where users report application or performance issues on browsers
There are two main options:
1. import the HAR file into the following Google online URL: This provides an easy interface to view timing info, as well as request / response HTTP headers and response payloads. The only concern is that you may be uploading internal information to a public site
2. Using Fiddler: After downloading and installing Fiddler locally on a workstation, you can open HAR files with Fiddler by doing the following:
The advantage with Fiddler is that any sensitive corporate Application stays internal.