Polymer is a web library, built on top of Web Components, and designed to leverage the evolving web platform on modern browsers.
Spin.js dynamically creates spinning activity indicators that can be used as resolution-independent replacement for AJAX loading GIFs.
Spin JS is leading in Top 10K Sites, Top 100K Sites, Top 1M Sites and The Entire Web.
In terms of market share, Polymer is clearly lagging behind, losing to Spin JS in all segments.
Spin JS has better usage coverage in more websites categories. Including Science & Education, Computers Electronics & Technology, Arts & Entertainment, Travel & Tourism and 20 other categories.
Polymer hasn't got a lead over Spin JS in any websites category.
Spin JS is leading in most countries, including United States, Russia, Germany, Taiwan and 161 other countries.
Polymer hasn't got a lead over Spin JS in any country.