kilian 427 days ago. link 3 points ▲ ▼It's true that responsively is copying a lot of the features that Polypane pioneered. It's one of the increasing number of copycats. They all follow the UI that Polypane introduced since I publicly announced the beta back in 2017, and even more after I launched it early last year. Still there are tons of features that are unique to Polypane. Just listed on the homepage: Polypane reads out the CSS and parses the media queries to create panes, it has a custom element inspector that lets you inspect and edit all sizes at the same time (instead of one by one), it has pixel perfect social media previews and meta information. There's zero-configuration live reloading built in and beyond that there's much more emulation options, accessibility tests and overlays, like a contrast checker, color blindness simulators and layout debugging. Just in the intro video you'll see a ton of stuff unique to Polypane.