Detect Polyfill
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.
Detection looks at script sources across 1 fingerprint rules among the site's public responses.
01
Websites using Polyfill
Loading website list…
02
Signal classes
PluginView evaluates public page signals in these classes when identifying Polyfill. Individual fingerprint rule bodies are proprietary and are not published.
- Script sources
03
Example public indicators for Polyfill
Illustrative indicators derived from public catalog metadata for Polyfill. A live scan may match additional proprietary rules beyond these examples.
- polyfill.io/v
04
What a detection means
- Establishes
- One or more public signals on the scanned page matched a known Polyfill signature (1 rules) at the time of the scan.
- Does not establish
- A sitewide install of Polyfill, an active vendor contract, exclusive use, or that Polyfill is still in place today.
05
How to check a site for Polyfill
- 1. Enter the website URL in the scan form — homepage, pricing, checkout, or login pages usually expose the strongest Polyfill signals.
- 2. PluginView reads only public responses (script sources) and scores them against the Polyfill signature set (1 rules).
- 3. Review the confidence score and text explanation for Polyfill on the results page.
06
FAQ: detecting Polyfill
- Can PluginView detect Polyfill without logging in?
- Yes. PluginView only reads publicly accessible responses when checking for Polyfill — typically script sources. It does not bypass authentication or paywalls.
- What category is Polyfill?
- Polyfill is classified under JavaScript libraries in the PluginView directory.
- How many fingerprint rules cover Polyfill?
- This reference currently tracks 1 fingerprint rule across script sources. Individual rule bodies are proprietary and are not published.
- What public signals suggest a site uses Polyfill?
- Illustrative public indicators for Polyfill include polyfill.io/v. A live scan may match additional proprietary rules beyond these examples.
