Partytown is a lazy-loaded library to help relocate resource intensive scripts into a web worker, and off of the main thread. Its goal is to help speed up sites by dedicating the main thread to your code, and offloading third-party scripts to a web worker.
Even with a fast and highly tuned website following all of today’s best practices, it’s all too common for your performance wins to be erased the moment third-party scripts are added. By third-party scripts we mean code that is embedded within your site, but not directly under your control. A few examples include: analytics, metrics, ads, A/B testing, trackers, etc.