Polyfill
Polyfill.io is an open-source 
JavaScript library that provides modern web API features to older browsers that do not natively support them.
It was originally owned by the Financial Times web team, then moved under community management, and after a supply chain attack in 2024 involving its cdn.polyfill.io domain, the service was discontinued and is now safely mirrored and maintained by 
Cloudflare and 
Fastly.
According to our data, Polyfill is the 5th most popular JavaScript library on the web.
It has 10.5% of the JavaScript library market share and is detected on 7.8% of all websites.
- 🏷️ Previous name
- Polyfill.io
- 🔗 Links
💸 Pricing
Polyfill is available for free.
📊 Rankings and Market Share
- JavaScript Libraries
- Rank: 5
- Market share: 10.5%
🏆 Polyfill Awards
- 🥈 Second most popular in Russia in the JavaScript Libraries category.
- 🥈 Second most popular in Belarus in the JavaScript Libraries category.
- 🥉 Third most popular in Switzerland in the JavaScript Libraries category.
- 🥉 Third most popular in Kazakhstan in the JavaScript Libraries category.
- ⭐ 4th most popular in the United Kingdom in the JavaScript Libraries category.
- ⭐ 4th most popular in Spain in the JavaScript Libraries category.
- ⭐ 4th most popular in France in the JavaScript Libraries category.
- ⭐ 4th most popular in Belgium in the JavaScript Libraries category.
- ⭐ 4th most popular in New Zealand in the JavaScript Libraries category.
- ⭐ 4th most popular in Lithuania in the JavaScript Libraries category.
⚡ Sites Using Polyfill
We have data on 297,175 websites that use the Polyfill JavaScript library. Here is a list of some of the top ranked ones.
The highest rated site using Polyfill is netflix.com.
| # | Website | Rank | Country | Language |
|---|---|---|---|---|
| 1 | #19 | United States | English | |
| 2 | #38 | United States | English | |
| 3 | #55 | English | ||
| 4 |  wordpress.com |
#83 | United States | English |
| 5 |  baidu.com |
#90 | China | Chinese |
| 6 |  amazon.de |
#122 | United States | English |
| 7 |  qq.com |
#144 | China | Chinese |
| 8 | #146 | United Kingdom | English | |
| 9 | #161 | Netherlands | English | |
| 10 |  yandex.com |
#195 | Russia | English |
| 11 |  bilibili.com |
#212 | China | Chinese |
| 12 | #222 | Singapore | English | |
| 13 | #225 | Korea | Korean | |
| 14 | #234 | Poland | Polish | |
| 15 | #262 | Indonesia | ||
| 16 |  amazon.it |
#274 | United States | British English |
| 17 |  amazon.fr |
#276 | United States | English |
| 18 |  ok.ru |
#295 | Russia | English |
| 19 | #319 | United States | English | |
| 20 | #342 | United States | English |
📈 Usage Statistics
Most of the sites that use Polyfill:
- are located in the United States
- have content in English
- use the .com domain extension
- fall into the Business category.
Most of the sites using Polyfill are from the United States, Russia, and Japan.
- United States 17.1%
- Russia 7.9%
- Japan 7.1%
- United Kingdom 6.5%
- Spain 4.9%
- Italy 4.4%
- France 4.2%
- Germany 3.7%
- Australia 3.1%
- Other 41.1%
Most Polyfill users speak English, Russian, or Spanish.
- English 47.7%
- Russian 8%
- Spanish 6.8%
- Japanese 6.3%
- French 4.7%
- German 4.2%
- Italian 3.6%
- Portuguese 2.6%
- Dutch 2.5%
- Other 13.6%
The Polyfill JavaScript library is especially popular on .com, .org, and .ru top-level domains.
- .com 40.7%
- .org 6.2%
- .ru 5.7%
- .co.uk 2.6%
- .it 2.5%
- .de 2.4%
- .net 2.1%
- .nl 1.8%
- .com.au 1.8%
- Other 34.2%
The primary market segments for websites utilizing Polyfill include business, marketing and merchandising, and online shopping.
- Business 20.3%
- Marketing/Merchandising 12.8%
- Online Shopping 9.2%
- Education/Reference 6.3%
- Blogs/Wiki 5.4%
- Internet Services 4.6%
- Travel 4.3%
- Health 3.7%
- Entertainment 3.6%
- Other 29.8%
🔢 Polyfill Versions
The most popular version of Polyfill is 6.26, used by 12.5% of sites where versions were detected. In addition, 10.4% of sites use Polyfill 1.0, and 10.4% use Polyfill 3.109.
- 6.26 12.5%
- 1.0 10.4%
- 3.109 10.4%
- 7.12 10.4%
- 0.1 8.3%
- 7.0 8.3%
- 7.11 6.3%
- 1 4.2%
- 6.23 4.2%
- Other 25%
🕵️ Similar Technologies
These are some of the best Polyfill alternatives.
🆚 Compare Alternatives
Compare Polyfill to…
- 🕵️ Similar libraries
- ⭐ Market leaders
- 💡 More alternatives
- 🔎 All options
💬 Frequently Asked Questions
Where is Polyfill from?
Polyfill is from London, United Kingdom.
Can I use Polyfill for free?
Yes, it is a free JavaScript library.
Which country uses Polyfill the most?
The majority of Polyfill users are from the United States.
Who uses Polyfill?
According to our data, Polyfill is used on thousands of sites, including such established ones as netflix.com,
archive.org, and
theguardian.com.
Is Polyfill used on government websites?
In total, we found Polyfill on 120 government sites in the United States.
Do academic institutions use Polyfill?
Yes, quite a few! In total, we know of 331 academic websites in the United States that use Polyfill.
How does Polyfill compare to the competition?
Polyfill is a very popular JavaScript library, second only to 4 other JavaScript libraries we track.
What are the alternatives to Polyfill?
Alternatives and possible competitors to Polyfill may include 
Regenerator, 
Babel, and 
👉 See Also
- ✨ Related technologies
🗃️ About This Data
- We evaluate the popularity of technologies based on the number of websites where we detect their usage.
- Technologies without a detectable web footprint, and those we do not track, are not reflected in the calculated market share.
- This report is based on the analysis of 3,823,966 websites.
- Statistics were last calculated on .
- For more details, see our methodology and disclaimer.