How can I know if browser is Chrome vs Firefox from web extension popup JavaScript?

Question

I am using the chrome namespace for both Chrome and Firefox, but would like to know which browser is running the web extension.

Answer 1

Links to extension resources have different schemes in Chrome and Firefox.

const isFirefox = chrome.runtime.getURL('').startsWith('moz-extension://');
const isChrome = chrome.runtime.getURL('').startsWith('chrome-extension://');