Quote:Third Party Web is an initiative to analyze the cost of third-party scripts on websites to provide Internet users and developers with actionable information.

The project has four simple goals:

1. Quantify the impact of third-party scripts that run on the top 1 million sites according to Alexa.
   
   
2. Identify scripts that have the greatest performance costs.
   
   
3. Provide developers with information.
   
   
4. Incentivize responsible script behavior.
   

The project team runs two scans on about four million sites per month using Lighthouse on mobile to identify third-party scripts and the performance impact they have.
According to the data, about 65% of all script execution time is caused by roughly 800 origins; the top 100 origins account for about 59% of all script execution time on the analyzed sites.

Read also:  Extensions may impact performance.

The project sorts scripts into categories such as ads, social, analytics, or video to make it easier to compare the performance impact of related scripts.

Full reading: https://www.ghacks.net/2019/02/15/third-party-web-an-analysis-of-third-party-script-costs/