Polyfill is a service which accepts a request for a set of browser features and returns only the polyfills that are needed by the requesting browser.
Polyfill.io is leading in Top 10K Sites, Top 100K Sites, Top 1M Sites and The Entire Web.
In terms of market share, Sizzle is clearly lagging behind, losing to Polyfill.io in all segments.
Polyfill.io has better usage coverage in more websites categories. Including Lifestyle, Food & Drink, Science & Education, Law & Government and 10 other categories.
Sizzle is leading in Computers Electronics & Technology, E-commerce & Shopping, Games, Gambling and 6 other categories.
Polyfill.io is leading in most countries, including United States, United Kingdom, Canada, Japan and 158 other countries.
Sizzle is leading in South Korea and China.