macOS Catalina is finally available on all eligible Mac and MacBooks. The latest software update, announced during WWDC 2019, brings several new features to the table, including a split-up iTunes — Music, Podcasts, and Video are each now standalone apps — Apple Arcade, and Sidecar, a feature that lets users use their iPad as a secondary display.
Unfortunately, that last feature doesn't work on all MacBook models, even though they're totally eligible to run macOS Catalina. The only ones that support Sidecar are the following:
• MacBooks from 2016 or later — the second generation of Apple's ultra-thin laptop line, now discontinued.
• MacBook Airs from 2018 or later — better known as Apple's recent redesign of the MacBook Air.
• MacBook Pros from 2016 or later — the ones with the butterfly keys.
macOS Catalina Sidecar Will Not Work On All Macs
In other words, those who own MacBooks without butterfly keyboards are unfortunately not getting Sidecar, as this Apple white paper notes. Apple didn't explain why this is, but it's common for the company to keep some features locked to newer models. Typically, the reason is some models aren't equipped with the necessary hardware to run that feature. Supposing this is the case, it's hard to guess what hardware requirement non-Sidecar MacBooks could be lacking, though.
The Verge guesses that it could be because of chipsets. The white paper mentions Sidecar needs Intel's Skylake or newer CPUs to run. It's worth noting at this point that Skylake or later adds support for the HEVC video codec, and Sidecar most likely relies on this codec to mirror to cast content onto a secondary display. To be sure, this isn't confirmed to be the case, but it's plausible. Nearly all Mac models have always been able to connect to secondary display, so this doesn't make sense on the surface level. Still, the iPad may have its own quirks that renders low-powered Macs incapable of pushing content to it.
You Also Need A New-Ish iPad
It's not just newer MacBooks, though. People would also need to have fairly recent iPads to run the feature, and it will have to support Apple Pencil. All iPad Pro models are supported, says Apple, plus the sixth-generation or newer iPad, fifth-generation iPad mini, and third-generation iPad Air. Regardless of the model, it must be on iOS 13 already.
Sidecar also works with a number of desktop Macs, including Mac minis from 2018 or later, iMacs from late 2015 or later, all iMac Pros, and the reinvented Mac Pro, which has yet to be released.