WIRED: Canonical burr grinders
All the grinders we featured are what’s known as conical burr grinders. Coffee beans are ground between two rings of burrs that crush and grind up the beans. There are also flat burr grinders, but I recommend sticking with the conical variety. The price difference is negligible, and the result is much better.
TIRED: Blade grinders
The $ 14 Krups model you see here is a totally fine blade grinder. It does its job as intended. Blade grinders are made more like blenders, with a chopping blade that spins around like a food processor. The problem is that blades don’t produce even results. Some of your coffee will be fine powder at the bottom, and at the top you’ll have bits too large for even French press. The result is an inconsistent, unpredictable brew. These grinders are cheap, and yes, using fresh beans in a blade grinder is better than buying ground coffee. (You can learn how to shake the beans to even your grind just a little.) But if you can afford it, I highly recommend going with one of the above options.
(Also TIRED: We tested the Cusinart Supreme Grind because of its low price, but it was loud, the grind wasn’t as even as we wanted, and the motor gave out on our unit after a few weeks. We recommend you stick to $ 100+ models for electric burr grinding.)