Scott Whittaker

Access Chrome developer tools custom emulated device list

In the current day job I often need to test applications in the browser that require a custom User Agent string. In Chrome, these can be added via the Device Toolbar. See add a custom device.

I wanted to save the list of custom User Agent strings that I had added to Chrome, I couldn’t find an export utility and I could of course have just copied and pasted them somewhere but I was curious where these values were stored. A quick search result suggested that the data is saved on disk in Chrome preferences.

Chrome preferences location on disk on a mac

On a mac the Preferences file can be found here…

/Users/<username>/Library/Application Support/Google/Chrome/Default/Preferences

Preferences are saved as a JSON object and the custom emulated devices are saved as a JSON string on the following property…

devtools.preferences.customEmulatedDeviceList

Emulated device list

Here is the parsed list of emulated devices that I currently have added to Chrome.