Definition
A .HAR (HTTP Archive) file is a JSON file that records network traffic between a browser and a server. It is used to diagnose network and performance problems in web applications.
What is a HAR file used for?
- Debugging network problems: It allows you to analyze HTTP requests and responses, load times, and errors
- Performance analysis: shows how long it takes a web page to load resources such as CSS, JavaScript, images, and APIs
- Debugging security problems: it can reveal suspicious requests, unwanted redirects, or vulnerabilities such as man-in-the-middle
- Reproducing bugs: by recording all HTTP traffic, it can be used to replicate issues reported by users.
How to generate a HAR file?
In Google Chrome, for example:
- Open Developer Tools (F12 or Ctrl+Shift+I / Cmd + Option + I on Mac).
- Go to the Network tab.
- Reload the page to capture traffic.
- Right-click a request, select Save all as HAR with content, and save the file.