A recurring question: why does the extension find video on dozens of sites but sees nothing on Netflix or Prime Video? The short answer is that those services deliver video a different way. And it is not a matter of not having got round to it.
How DRM works
DRM is technical content protection. On paid services the video arrives in your browser already encrypted. Only a dedicated module inside the browser itself can decrypt it — in Chrome that is Widevine. The module is closed: it receives a key from the server, decrypts the stream and hands frames straight to the graphics stack.
The key point is that an extension sits outside that chain. It can see data crossing the network, but those are encrypted bytes. It has no key and cannot have one: the browser does not hand it to any page code, add-ons included.
So a "Netflix downloader" is either an empty shell or a program doing something other than advertised. Defeating Widevine from an extension is impossible in principle, not merely unimplemented.
Which services work this way
- Subscription streamers: Netflix, Amazon Prime Video, Disney+, Max, Apple TV+.
- Education platforms with paid access to course video.
- Subscription sports broadcasts.
- Some corporate video platforms.
The tell is simple: if a service is paid and offers offline viewing inside its own app, it almost certainly uses DRM. That is exactly why their offline mode only works within the app — the file is stored encrypted and is useless outside it.
Why we do not try to get around it
Beyond the technical impossibility there is the legal side: circumventing technical protection measures is prohibited under copyright law, and Chrome Web Store policy explicitly bars extensions that do it. An extension advertising such a feature gets removed from the store.
So this is not caution, it is a condition of the product existing. We would rather state plainly where the extension works and where it does not than have you discover the limit after installing.
What to do instead
- The service's own offline mode. Nearly every subscription streamer lets you download a title in its mobile app for the length of your subscription — the legitimate way to watch on the move.
- Legal free archives if you specifically need a file: the public domain, national film archives, openly licensed work.
- Open platforms. On sites without DRM — Vimeo, VK, Bilibili and others — the extension works normally.
If the goal is saving a particular clip rather than a subscription film, have a look at the supported platforms: eleven services with dedicated support, plus a generic mode for other unprotected sites.