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What is a HAR file (HTTP Archive)?

HAR file (HTTP Archive) is a .har format that stores a log of the browser's interaction with the network. It contains all HTTP(S) requests, responses, headers, bodies, status codes, cookies, and load times. It is used...

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This content has been automatically translated from Ukrainian.
HAR file (HTTP Archive) is a special file format .har that stores the log of a web browser's interaction with the network.
Essentially, it is a record of all HTTP(S) requests and responses that occurred during the page load. It contains:
  • addresses of all resources (HTML, CSS, JS, images, API requests, etc.),
  • the execution time of each request,
  • headers,
  • request and response bodies (if enabled),
  • status codes (200, 404, 500, etc.),
  • information about redirects, cookies, caching.
Used for:
  • diagnosing website issues (slow loading, API errors),
  • analyzing traffic between the client and server,
  • reproducing or debugging errors in technical support,
  • security checks.
A HAR file can be captured in most browsers (Chrome, Firefox, Edge) via DevTools → Network tab → Export HAR.
Screenshot 2025-08-25 at 18.15.15.png

How to open a HAR file?

The easiest way is a text editor or code editor. But let's look at it in more detail.
Screenshot 2025-08-25 at 18.17.27.png
 The simplest ways
  • Any text editor (Notepad, VS Code, Sublime Text) - to see the "raw" data in JSON format.
  • Browser - Chrome, Firefox, Edge have built-in HAR viewers:
    • Open DevTools → Network tab → drag the HAR file there, and it will display as a list of requests.
Convenient viewers
  • Google HAR Analyzer - a web service from Google for visualization. https://toolbox.googleapps.com/apps/har_analyzer/
  • HAR Viewer (online tools like harviewer.org).
  • Fiddler, Charles Proxy, Wireshark - professional network traffic analysis tools that support HAR import.
https://toolbox.googleapps.com/apps/har_analyzer/
https://toolbox.googleapps.com/apps/har_analyzer/

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