Tested on a car with vertical vents.

The BE Universal Smartphone Car Air Vent Mount is the rare phone holder that works well with vertical-slat vents. It locks onto your car with a small clip that is tightened by first turning and then pressing down–and it hangs on very tightly. In over nine months of use, I haven’t had to readjust it once.

It also grips to phones firmly, no matter how you rotate the 360-degree ball joint. Supported sizes are phones ranging between 1.9 to 3.7 inches in width, which covers all current iPhones and most Android models.

Overall construction is solid as well. BE Universal uses a rigid, dense plastic, lined with soft foam pads that cushion and protect your phone from scratches.

This mount’s only downsides are an incompatability with round vents, and its larger size. If those aren’t issues, this inexpensive phone holder is a great option. –Dan Masaoka

Tested in a car with horizontal vents.

iOttie’s Easy One Touch 4 Air Vent Mount ($24.95 MSRP; $19.95 on Amazon) is a solid pick, both in price and functionality. This mount has two parts, but it’s very easy to assemble: Just snap the vent clamp into the back of the phone mount, and attach it to your air vent using the spring-loaded clamp. The mount keeps your phone in place thanks to two arms that hug it tightly, using a “lock and release” system.

The Easy One Touch 4 fits phones between 2.3- and 3.5-inches wide—I tested it out using an iPhone 8, iPhone 8 Plus, and iPhone X with and without cases, and it fit the bill for all three of Apple’s current models. It’ll work just fine for Android phones within that size range, too.

This iOttie mount held up well during my testing. The hinge continued to keep my iPhone held upright without sagging, and the mount stayed firmly clasped to the air vent without falling off due to my phone’s weight. Plus, it rotates 360-degrees to help you find the perfect viewing angle, be it in landscape or portrait orientation. –Leah Yamshon

Tested in a Honda Accord (1999)

Installation of Koomus’s grip-style, CD-slot mounted phone holder is simple, with just one lever that locks the whole unit in place. This method still results in a sturdy hold, though–while Koomus includes three rubber spacers to increase the clamping force, we didn’t need it. The mount itself can be positioned in a variety of ways: Its arm tilts up and down, and you can insert it with the mount pointed up or facing down.

The grip-style clamp has surprisingly light tension, allowing you to mount a phone with just one hand. It accommodates larger phones, even with bulkier rugged cases. I successfully put a Nexus 6P and a Pixel 2 XL in the clamp, though the Pixel 2 XL in an Otterbox case was the most difficult of the combinations I tried.

One potential issue with this Koomus model is its size. It’s quite large, so depending on the placement of your CD player, it’ll block access to controls. The arm that holds the phone in place also uses a simple friction ball joint with no ability to increase tension down the road once it’s worn in. While we had no issues with it new, we can foresee it drooping eventually. –Gordon Mah Ung

Tested on a car with horizontal vents.

Car mounts that just clip onto the slats in your air-conditioning vent are incredibly convenient. They don’t block your view or muck up your dashboard with adhesive, and they work with cars lacking a CD player. And in those blazing summer months, the A/C blowing right onto the back of your phone will help keep it from overheating.

Kenu makes one of the best grip-style vent clips. It’s minimalist in design but durable, with a spring-loaded side clip big enough to fit the even large phones like Plus-model iPhones and Galaxy Notes. (If you own a phone under 5-inches, you’ll want to buy the smaller version of this mount.) The vent clip has grips for thick or thin vent slats, so it’ll work in most cars. And since it can rotate, you can use it with angled AC vents or turn your phone to landscape orientation.

At an MSRP of $25, it’s not one of the cheapest vent mounts on the market. But the durability and careful design are worth a few extra bucks. –Jason Cross

Tested in a car with round vents.

You’re unlikely to find a more simple, unobtrusive, and inexpensive option than this $8 phone holder.

Slits on the magnetic mount’s short, rubberized stem allow it to slip onto your car’s air vent. To attach your phone to the mount, you’ll need to apply one of the two included metal plates to your phone directly or slip the plate into your phone’s case.

The magnet combination is rated to hold today’s largest phones, such as the Galaxy Note 8 or iPhone X, and in my experience with a Pixel XL, the device remained secure while making the screen visible as I drove.

The downsides are that it blocks a vent and/or absorbs any hot or cold air your vent is emitting. Still, it’s an exceedingly simple solution for making your phone accessible while you drive. –Katherine Stevenson

Tested in a car with horizontal vents.

The Square Jellyfish Jelly-Grip Car Vent Mount is a mouthful, but it’s an excellent smartphone vent mount for your car. This phone holder uses an adjustable, solid metal hook that extends to slide through a vent (from 3/8” to 1” deep) and over its horizontal louvers. Square Jellyfish says that the mount can be used with vertical louvers, too, though we didn’t test that. If you have round louvers, it won’t work.

The spring-loaded side grips grab phones up to six inches wide tightly—almost too tightly. Actually mounting the phone required placing it face down on a seat and grabbing it with the grips, then placing the whole contraption within the vent. You can also slide the phone out to remove it, but be careful of any side-mounted buttons.

The tradeoff? An absolutely secured phone that isn’t going anywhere. And since the grips swivel on a ball mount, you can still position your phone for easy viewing. As a final bonus, the manufacturer offers a lifetime warranty: Send Square Jellyfish a picture of the problem, and the company will ship a replacement, free of charge. –Mark Hachman