Importing from Chrome

To record a performance profile in Chrome, open the developer tools and switch to the performance tab.

Click the record button.

When you're done recording, click the "Stop" button.

When it's finished processing, click the "Save profile" button.

This should save as a filename like Profile-20180820T095940.json.

You should be able to open that file in https://www.speedscope.app/.

To view it offline, you'll need to install speedscope via npm:

npm install -g speedscope

Then you should be able to open it like so:

speedscope /path/to/profile.json