Smartphones are notoriously grody. You've probably heard the toilet seat analogies before: The average phone is anywhere from seven to 10 times dirtier than most porcelain thrones, depending on who you ask, and one in six is supposedly contaminated with fecal matter. (Truly sinister stuff.) If you're checking your phone as often as most people — that is, about once every 10 minutes — that's a lot of exposure to a lot of bacteria.
If your phone's starting to get gross, Apple, Google, and major Android manufacturers like Samsung, LG, Huawei, and Motorola all recommend swabbing it down with a soft, lint-free cloth, a hint of warm, soapy water, and a dab of rubbing alcohol. But as with cleaning any electronic device, this requires an extremely careful hand: Any excess moisture will do some serious damage if it gets into a port or crack. (Take it from someone who ruined an Xbox controller this way: It doesn't take much.) You also risk stripping the screen's protective coating, which makes it more prone to smudges and fingerprints.
Consider, too, that you really have no way of telling whether you missed a spot when you give your phone a quick wipe-down — those poop germs could still be chilling there while you text, talk, and watch TikTok. There's got to be a better way, right?
That's the general idea behind ultraviolet (UV) phone sanitizers, anyway.
What is a UV phone sanitizer, exactly?
Sanitizing devices that use UV light to kill pathogens and superbugs have been around in the medical field for decades now, but consumer-friendly adaptations are a more recent development and have gained significant popularity amid the COVID-19 pandemic. (See also: UV air purifiers and UV sanitizing wands.)
A UV phone sanitizer is essentially just a small plastic or metal box containing a couple of UV bulbs or lamps, which shine onto your device during the disinfection cycle. Aside from avoiding moisture, fumes, and residue, the most obvious draw is the sheer convenience factor: You just pop your phone into the sanitizer's chamber, close its lid, and let it do its thing for about five to ten minutes.
For best results, make sure you take your device out of its case before sanitizing it — you can run that through separately afterward. (Other small objects like PopSockets, keys, credit cards, glasses, smartwatches, and earbuds should fit in there, too.)
How does UV light kill germs?
UV light is a form of electromagnetic radiation you usually encounter in the form of sunlight, though it can also be recreated using artificial light sources. There are three different types of UV rays:
UV-A rays have the longest wavelengths. You'll find these in tanning beds, bug zappers, and in the blacklights of your local club.
UV-B rays have slightly shorter wavelengths. These can help skin produce Vitamin D3 (but may also cause sunburn) and are mostly used in tanning beds alongside UV-A radiation.
UV-C rays have the shortest wavelengths. These are typically used for disinfection purposes, as they can damage microbes' DNA. This either kills them outright or prevents them from functioning and reproducing.
Note: All mentions of UV light hereafter refer to UV-C rays specifically.
Is UV light dangerous?
UV light is far more dangerous to a microbe than a human being, but the U.S. Food and Drug Administration still recommends exercising some caution around it: "Direct exposure of skin and eyes to UV-C radiation from some UVC lamps may cause painful eye injury and burn-like skin reactions. Never look directly at a UVC lamp source, even briefly."
The FDA further notes that UV light can degrade plastic and polymers, but fret not: You'd need hours of continuous exposure to do any notable damage to your phone.
Do UV phone sanitizers really work?
PCMag's consumer electronics analyst Steven Winkelman has already tackled this topic in a thorough explainer. (PCMag is owned by Mashable's published, Ziff Davis.) We won't rehash the whole thing, but the gist of it is this: Kind of.
While UV light itself is really good at eliminating and stopping the spread of certain bacteria (including E. coli and Salmonella), the kinds of UV sanitizers being sold to the public are pretty dinky compared to the ones used in hospitals.
"Many of the UVC lamps sold for home use are of low dose," the FDA says, "so it may take longer exposure to a given surface area to potentially provide effective inactivation of a bacteria or virus."
To that end, it's also important to note that while most manufacturers say their phone sanitizers are 99.99% effective against common germs, very few can back up their claims with third-party lab testing.
We already know that hand-washing, wearing masks, social distancing, and getting vaccinated are quite good at keeping us germ-free — and those methods are all free or extremely cheap. All things considered, UV sanitation should be your "second line of defense" against viruses and bacteria, Winkelman says.
Are UV sanitizers effective against COVID-19?
The National Academies of Sciences, Engineering, and Medicine have confirmed that UV light is capable of destroying SARS-CoV-2, the virus that causes COVID-19, but that also comes with a pretty big caveat: No consumer-grade phone sanitizers have been lab-tested against COVID, even the rare few that have undergone testing against other germs.
Keep in mind, too, that COVID is primarily an airborne virus. "[Studies] show the virus is rarely viable on surfaces," Winkelman writes, "and the CDC states that transmission from contaminated surfaces 'is not thought to be a common way that COVID-19 spreads.'"
If you're thinking about getting a UV sanitizer for the sole purpose of protecting yourself from COVID, you're probably better off with a face mask or respirator and a Moderna or Pfizer jab.
What's the best UV phone sanitizer?
If your ears perked up at that previous mention of PhoneSoap, it's either because you caught its Shark Tank episode back in 2015, you heard about its partnership with Otterbox, or just because it's easily the biggest name on the market. The company sells a wide range of UV sanitizing devices that have all undergone extensive lab testing, including several full-featured phone sanitizers with built-in chargers, special acoustic outlets that let you hear notifications, and antimicrobial cables.
For these reasons, we recommend PhoneSoap's products above all others for most use cases. (There are a few exceptions.) Here's the lowdown.