BrowserTraySwitch is described as 'super tiny little system tray utility (only 90k) to help you quickly change your default browser'. There are more than 10 alternatives to BrowserTraySwitch for a variety of platforms, including Mac, Windows, Linux, Microsoft Edge and Google Chrome. The best alternative is Choosy. It's not free, so if you're looking for a free alternative, you could try Browserosaurus or Browser Select. Other great apps like BrowserTraySwitch are Account Surfer (Paid), LinCastor Browser (Freemium), Browser Tamer (Free) and Braus (Free, Open Source).
Browserosaurus is an open-source (MIT license), Electron-based app for macOS. It works by setting itself as the default browser; any clicked links in non-browser apps are now sent to Browserosaurus where it’ll present you with a menu of all your installed browsers.
Browser Select is a utility to dynamically select the browser you want instead of just having one default for all links. similar to the prompt in android to choose a browser when a link in a non-browser app is clicked/touched.
When you click on a link, LinCastor Browser asks you to choose a browser to load the link with from a menu. Menu can contain a browser, an application but also AppleScript, shell script, Automator Workflow or even OS X share service.
A small application to select a browser every time you click a link anywhere. This is especially useful if you have multiple browsers or profiles, and you want to be able to open certain links in certain browsers.
One tool to rule them all Get virtually as many default web browsers as you want. With Browser Fairy you can you can even have individual default web browsers for every app and literally every web page.
Take control of the many browsers that you may have installed on your Mac. Can launch links from just about any application. Uses no resources when idle. Works with just about any browser. Highly configurable appearance lets you choose colors, size, and more.