In the Chrome Developer Tools you can store a JavaScript as a snippet. Alternatively you could run a JavaScript in the "Console". If you use the same script often it makes sense to store it as a snippted.
- Open Develper Tools (⌥ + ⌘ + i)
- Go to "Sources"
- Open "Snippets"
- "Add new snippet"
- Copy & the snippet code from this repository
- Open the Developer Tools
- Open the Command Center (⌘ + O)
- Type
! snippet-name
and press enter - If the script produces an output you should see it in the "Console"
- Some scripts copy the output automatically in the Clipboard