Ultimately your first consideration when choosing one of the best capos should be to choose one that fits your guitar. Most brands offer a range of options, so if you see a capo you like, there’ll probably be one designed to fit your guitar.
Generally, capos are designed to fit as universally as possible, so you shouldn't need to buy a specific capo unless your neck or fretboard is exceptionally different from the norm. A capo that fits on a regular acoustic guitar will most likely do the same job on an electric. There are, however, specific capos for Ukuleles, 12-string guitars, and classical guitars.
The reason for this is obvious with ukuleles as they're much smaller, less so with the other two. Because of the extra set of strings on a 12-string acoustic or electric, you'll need a higher tension to effectively clamp down the strings. On a classical guitar, it comes down to the flat fretboard radius as we mentioned before, which requires a specific capo design to work properly.