You can see all the service workers running crap on your system if you visit: chrome://serviceworker-internals/
in your browser.
It lists service worker internals such as installation status, the running script and the service worker scope.
Scope: https://twitter.com/
Registration ID: 0 (unregistered)
Navigation preload enabled: false
Navigation preload header length: 4
Active worker:
Installation Status: ACTIVATED
Running Status: RUNNING
Fetch handler existence: EXISTS
Script: https://twitter.com/sw.js
Version ID: 111
Renderer process ID: 68693
Renderer thread ID: 19
DevTools agent route ID: 52
Client:
ID: fcf2a23e-9af3-4001-b196-c942340be16a
URL: https://twitter.com/stefanjudis
The page also includes actions for every service worker including an unregister
one.
To clear them out in bulk, open dev-tools -> console and paste this in and hit enter
$$('[data-command="unregister"]').forEach(b => b.click())