How to generate Browse HAR Files

  • Updated on Jul 1, 2025
  • Published on Jun 30, 2025
  • 4 minute(s) read
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About this document

HAR files are usefull to get a detailed log of how a browser interacts with a website. This is essential for debugging complex issues, analyzing performance, and providing technical support with a complete record of network activity.

There are a few key reasons of why is good to export and use HAR files, mostly related to troubleshooting and performance analysis:

  • Diagnosing Performance Issues: If a webpage is slow, a HAR file can reveal which resources (images, scripts, etc.) are taking the longest to load. This helps developers pinpoint and fix performance bottlenecks.
  • Debugging Errors: When a page isn't loading or functioning correctly, the HAR file shows if any critical resources are failing to load or returning errors.
  • Sharing Network Information: Instead of trying to describe a complex network-related problem, a user can simply export a HAR file and send it to a developer or support team. This gives the technical team a complete and accurate picture of what's happening in the user's browser.
  • Analyzing Security: HAR files can be used to inspect the security of a web application by examining headers, cookies, and other security-related information.

Generate a HAR file in Google Chrome

  1. Open Developer Tools:
    • Right-click anywhere on the page you want to record.
    • Select "Inspect" from the context menu.
    • Alternatively, use the keyboard shortcut: Cmd+Option+I (on macOS) or Ctrl+Shift+I (on Windows/Linux).
  2. Select the Network Tab:
    • In the Developer Tools panel that appears, click on the "Network" tab.
  3. Start Recording:
    • Look for a round button in the top-left of the Network tab. If it's grey, click it to start recording network activity. It will turn red to indicate it's recording.
    • Check the "Preserve log" checkbox if you need to record activity across multiple page loads.
  4. Reproduce the Activity:
    • With the recording active, perform the exact actions on the webpage that you want to capture. For example, if you're debugging a login issue, go through the login process.
    • You will see network requests appearing in the panel as you interact with the page.
  5. Export the HAR File:
    • Once you have reproduced the activity, click the "Export HAR..." button (it looks like a download arrow) in the Network tab's toolbar.
  6. Save the File:
    • A "Save As" dialog will appear. Choose a name and location for your file and click "Save". The file will have a .har extension.

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Generate a HAR file in Mozilla Firefox

  1. Open Developer Tools:
    • Right-click on the page you want to record.
    • Select "Inspect" from the context menu.
    • Alternatively, use the keyboard shortcut: Cmd+Option+I (on macOS) or Ctrl+Shift+I (on Windows/Linux).
  2. Select the Network Tab:
    • In the Developer Tools panel, click on the "Network" tab.
  3. Start Recording:
    • The network monitor usually starts recording automatically when you open it. If it's paused, you can start it by clicking the play/pause button in the toolbar.
    • Click the "Persist Logs" option (it looks like a gear icon in some versions, or may be a checkbox) in the Network tab's toolbar if you need to record activity across multiple page loads.
  4. Reproduce the Activity:
    • With the recording active, perform the actions on the webpage that you want to capture.
    • You will see network requests appearing in the panel as you interact with the page.
  5. Export the HAR File:
    • Once you have reproduced the activity, right-click anywhere in the list of network requests.
    • From the context menu, select "Save All As HAR".
  6. Save the File:
    • A "Save As" dialog will appear. Choose a name and location for your file and click "Save". The file will have a .har extension.

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Generate a HAR file in Apple Safari

Part 1: Enable the Develop Menu (if you haven't already)

  1. Open Safari.
  2. Go to the Safari menu in the top-left corner of your screen and select Settings... (or Preferences... on older macOS versions).
  3. Click on the Advanced tab.
  4. At the bottom of the window, check the box that says "Show Develop menu in menu bar".
  5. You can now close the Settings window.

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Part 2: Record and Save the HAR File

  1. Navigate to the web page you want to record.
  2. Click on the new Develop menu in the menu bar and select Show Web Inspector.
    • Alternatively, use the keyboard shortcut: Cmd+Option+I.
  3. Click on the Network tab in the Web Inspector window.
  4. Check the "Preserve Log" option in the Network tab's toolbar (it looks like a small trash can icon with a gear or a circle around it in different versions). This will prevent the log from clearing when you navigate
    to a new page.
  5. Perform the actions on the webpage that you want to capture in the recording. You will see network requests appear in the list.
  6. Once you have captured the necessary activity, click the Export button in the top-right corner of the Web Inspector's Network tab (it looks like a box with an arrow pointing up).
  7. A "Save As" dialog will appear. Choose a name and location for your file, and click Save. The file will be saved with a .har extension.
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