Capture cards are a major part of content creation in the video game space, but the Nintendo Switch has specific needs due to the nature of the platform. We'll cover some of the required components to get Switch gameplay onto a stream or into a video editor, and get more than those low-resolution, 30-second clips the console's share button makes.
A capture card is a device that passes a video feed from a game console to another device that can record the video. Typically, these devices work by connecting the game console to the card, then having the card send one feed out to the TV (so the player can continue to play on the TV as usual) and another feed to a PC. The PC can then either save the recording to be edited later or, through encoding software like OBS or XSplit, broadcast the footage as a live stream. Given that this process requires the device to be capable of connecting to a TV through HDMI, it is not possible to use a capture card with a Switch Lite, so if content creation is the goal, drop the extra $100 and pick up the standard Nintendo Switch.
With Switch and every current-generation console, the question of which card works is easy to answer: just about all of them. The important thing will be choosing the best one. By most accounts, the answer will be the Elgato HD60 S, easily the world's most popular capture card. It connects to a TV and a Switch via two HDMI cables, and then sends the game feed to a PC through USB. From there, it can be used with Elgato's dedicated, free software for editing, streaming, color correction, audio balancing, and so on. Elgato specializes in this field and prides itself on being an end-to-end solution for streamers or people who capture game video. This card costs about $180 usually.
Alternatively, the AverMedia Live Gamer Portable 2 Plus is another great option specifically for Switch users. Its PC software isn't as robust as Elgato's but the device can record gameplay internally, so it doesn't require connecting to a PC. As a result, this is a portable gameplay recording solution, provided your definition of "portable" means you'll also have your Switch's dock with you. It records to a microSD card, so at some point, it'll require a PC to offload the video and subsequently upload it. This one can be found for about $170.
Why You Want to Use a Capture Card
Every version of the Nintendo Switch has a share button that can take screenshots and record up to 30 seconds of video, but with a downgrade in resolution and frame rate. It's great for quick uploads but for anything more, a capture device is essential. Most of them, including the two listed above, record at 1080p resolution and at 60 frames per second, which happens to match the maximum output of Switch games. So footage recorded with a capture card will look as good it possibly can.
Capture cards are also a requirement for streaming Switch games. PlayStation 4 and Xbox One have limited streaming (and editing, in the case of the former) capabilities, but the Switch lacks the option entirely. Anyone pursuing a streaming career will want a PC and a capture card to get footage to that PC at some point. Fortunately, the current models of capture cards work with just about every console and should also be compatible with the upcoming PlayStation 5 and Xbox Series X, so they're a great investment.