All important links you must remember as a web developer point of view so you quickly perform related tasks. I am listing below all related links that i found useful for site development and testing.
Google lists all CDN libraries at this URL
https://developers.google.com/speed/libraries/
- https://ajax.googleapis.com/ajax/libs/jquery/3.1.0/jquery.min.js
- https://ajax.googleapis.com/ajax/libs/angularjs/1.5.7/angular.min.js
- https://ajax.googleapis.com/ajax/libs/jqueryui/1.12.1/themes/smoothness/jquery-ui.css
- https://ajax.googleapis.com/ajax/libs/jqueryui/1.12.1/jquery-ui.min.js
- https://ajax.googleapis.com/ajax/libs/webfont/1.6.26/webfont.js
Few sites page seed testing sites
https://developers.google.com/speed/pagespeed/insights/
Mobile friendly test URLs
https://search.google.com/search-console/mobile-friendly
Few Network speed test sites
Google recaptcha admin URL
https://www.google.com/recaptcha/admin
Google AMP page testing URL
https://search.google.com/search-console/amp
Facebook share URL debugger
https://developers.facebook.com/tools/debug/
Google fonts URL
Projects Codes URLs