Oxygen is life, and using a pulse oximeter is an easy and painless way to see whether your body is getting enough of it.We’ve tested 13 fingertip pulse oximeters with people ages 2 to 78. We’ve also read dozens of clinical studies and spoken with experts who are working to improve at-home pulse oximetry, especially for people with darker skin.If you want an ultra-reliable, medical-grade pulse oximeter with FDA clearance, the Nonin Onyx Vantage 9590 is the one to get. It’s expensive, but unlike most recreational and wellness pulse oximeters, this one has undergone multiple independent clinical tests for accuracy — and it performed exceptionally well in each test.Many people will be just as well served by the Innovo Deluxe iP900AP, a non-FDA-cleared device marketed for recreational use that costs five times less but performed just as well in a small independent evaluation of accuracy.