How to Capture a HAR File for Troubleshooting

A HAR (HTTP Archive) file records the network activity between your browser and a website. Support teams often use HAR files to investigate slow page loads, failed requests, authentication issues, and unexpected errors.

This guide explains how to capture a HAR file in Google Chrome, Microsoft Edge, and Mozilla Firefox.

Select your browser:

• Google Chrome
• Microsoft Edge
• Mozilla Firefox

Before You Start

Before capturing a HAR file:

1. Close unnecessary browser tabs.
2. Open the page where the issue occurs.
3. Be prepared to reproduce the problem.
4. Note that HAR files may contain sensitive information such as URLs, request headers, and form data. Review the file before sharing it externally.

Google Chrome

Step 1: Open Developer Tools

Press F12 or Ctrl + Shift + I.

Alternatively:

Menu → More Tools → Developer Tools

Step 2: Open the Network Tab

Select the Network tab.

Step 3: Enable Network Logging

Ensure:

• The Record button (●) is red.
• Preserve log is enabled.

Step 4: Clear Existing Requests

Click the Clear button (⊘).

Step 5: Reproduce the Issue

Perform the actions that trigger the problem.

Step 6: Export the HAR File

Click on the Export HAR button

Choose a location and save the file.

Microsoft Edge

Step 1: Open Developer Tools

Press F12 or Ctrl + Shift + I.

Step 2: Open the Network Tab

Select Network.

Step 3: Enable Logging

Verify that:

• The Record button (●) is red.
• Preserve log is enabled.

Step 4: Clear Existing Requests

Click the Clear button (⊘).

Step 5: Reproduce the Issue

Perform the actions that generate the problem.

Step 6: Save the HAR File

Click on the Export HAR button

Choose a location and save the file.

Mozilla Firefox

Step 1: Open Developer Tools

Press F12 or Ctrl + Shift + E.

Alternatively:

Menu → More Tools → Web Developer Tools

Step 2: Open the Network Monitor

Select the Network tab.

Step 3: Enable Persistent Logs

Click the gear icon and enable:

Persist Logs

Step 4: Clear Existing Requests

Click the trash can icon.

Step 5: Reproduce the Issue

Perform the steps that cause the issue.

Step 6: Save the HAR File

Right-click within the request list and select:

Save All As HAR

Alternatively — Click on the gear icon and select to Save All as HAR:

Choose a location and save the file.

Common Tips

Capture From the Beginning

Start recording before reproducing the issue to ensure all relevant requests are captured.

Include Screenshots

When submitting a HAR file to support, include:

• A screenshot of any error message
• The exact time the issue occurred
• Steps to reproduce the problem

Compress Large HAR Files

HAR files can become large. If the file exceeds your email attachment limit:

1. Right-click the HAR file.
2. Select Send to → Compressed (zipped) folder.
3. Share the ZIP file instead.

Conclusion

Capturing a HAR file is one of the most effective ways to help a support team diagnose browser-based issues. By following the steps above, you can provide detailed network information that helps identify errors, performance bottlenecks, and failed requests more quickly.