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Google Chrome

1. Open Developer tools (in Menu > More tools > Developer tools or use Ctrl+Shift+I or F12).

2. Select the Network tab.

3. Make sure that the ‘Preserve log’ Preserve log option is checked so that all traffic is captured.

4. Access or refresh the page for which traffic needs to be captured or where a problem should be reproduced.

5. Perform the steps which lead to the behavior/issue.

6. Click the download icon ‘Export Export HAR...’ or right-click the Network capture pane and choose 'Save as HAR with content' and save the .har capture locally.
   

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7. On the Console tab, right-click, select ‘Save as’ Save as and save the .log file.

If you want use the whole browser area and keep logging in the background, just undock the Developer tools to a separate window using the More options menu.

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Firefox (41+)

1. Go to Menu > Web Developer > Network.

2. Reload the page you want to get the log for.

3. Perform the steps which lead to the behavior/issue.

4. Right-click and select ‘Save Save All as HAR’HAR.

5. Click the Console tab and select ‘Select All’ Select All.

6. Right-click, select ‘Copy Message’ Copy Message and save it as a .txt file.

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1. Open Developer Tools (F12).

2. Go to the Network tab and click the green arrow to start the tool.

3. Refresh the page to capture the logs.

4. Perform the steps which lead to the behavior/issue.

5. Click the 'Export captured traffic' icon and choose XML or HAR format.

6. On the Console tab, right-click and select ‘Copy All’ Copy All and save it as a .txt file.

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