Bookmarklets allow users to add custom JavaScript actions to their browsers, enabling personalized functionality like sending page URLs to external applications. They can interact dynamically with the current DOM and even launch local apps via custom URL schemes. While bookmarklets are powerful and versatile, they remain underutilized. Although setting them up can be cumbersome, the potential for seamless data flow between web browsers and local applications is significant. However, caution is advised against using untrusted sources for bookmarklets due to security risks.
https://silly.business/blog/bookmarklets-and-custom-url-schemes-are-criminally-underrated/