A HAR (HTTP Archive) is a file format that contains information about a web page’s performance, including the resources that the page loads such as images and scripts, the size of those resources, and the time it takes for them to load. The file can be used to analyze and troubleshoot website performance issues and can be exported from web browsers.
Below is shown how to create HAR files in the most popular web browsers. The instructions apply to both Windows and Mac computers.