How to create a HAR file

HAR (HTTP Archive format) is a JSON-formatted archive file for logging a web browser’s interaction with a site.

Instructions

Google Chrome

1. Open the Developer Tools from the menu (Menu > More Tools > Developer tools) or by pressing F12 (or Fn-F12) on your keyboard.

2. Click on the Network tab.

3. Look for a round button at the top left of the Network tab. Make sure it's red. If it's grey, click it once to start recording.

4. Turn on "Preserve log".

5. You can use the clear button (a circle with a diagonal line through it) right before trying to reproduce the issue to remove unnecessary header information.

6. Reproduce the issue.

7. Save the capture by right-clicking on the grid and choosing "Save as HAR with Content".

Mozilla Firefox

1. Start Firefox Developer Tools in Network mode (Top right menu > Developer > Network, or Ctrl-Shift-E / Cmd-Alt-E on macOS).

2. Turn on "Persist logs" on the right.

3. Reproduce the issue.

4. Save the capture by right-clicking on the grid and choosing "Save all as HAR".

Microsoft Edge

1. Open the Developer Tools from the menu (Menu > More Tools > Developer tools) or by pressing F12 (or Fn-F12) on your keyboard.

2. Open the Network tab.

3. Look for a round button at the top left of the Network tab. Make sure it's red. If it's grey, click it once to start recording.

4. Turn on "Preserve log".

5. Reproduce the issue.

6. Save the capture by right-clicking on the grid and choosing "Save as HAR with Content".