The Best Folding Sunglasses: A Buyer's Guide (2026)

Folding sunglasses solve one problem: the good pair you left at home, in the car or on the restaurant table. A pair that folds down to pocket size is a pair you actually have with you. But folding adds moving parts, and moving parts are where cheap sunglasses fail. Here is what to check before you buy, and how the main options compare.

1. Hinges matter more than anything else

A folding pair has more joints than a regular pair: usually one at the bridge and one at each temple. Every one of them takes stress each time you fold and unfold. Look for metal hinges held with screws you can tighten, not plastic pins. Spring hinges are a bonus: they flex outward so the temples grip without squeezing, and they absorb knocks instead of bending out of shape.

On Folds, the temple hinges are spring-loaded and open to 120 degrees, and a mini screwdriver comes in the box so you can keep everything tight.

2. Frame material: TR90 or acetate?

Most quality folding frames are made from acetate or TR90. Acetate is the traditional choice and has a great polished look, but it is heavier and can crack if you sit on it. TR90 is a flexible thermoplastic that bends under pressure and springs back, which suits something that lives in your pocket. It is also lighter and hypoallergenic. More in TR90 vs Acetate.

3. Lenses: polarized and UV400, not one or the other

These are two different things. UV400 means the lens blocks ultraviolet light up to 400 nanometers, covering UVA and UVB. That is what protects your eyes. Polarized means the lens filters horizontally reflected light, the glare that bounces off water, wet roads and windshields. That is what makes them comfortable to wear. Plenty of cheap folding sunglasses have one without the other, so check that both are clearly stated.

4. Impact safety

In the US, sunglasses must pass the FDA drop-ball impact test (21 CFR 801.410). Reputable brands will tell you their lenses have been tested. Folds lenses are impact tested to this standard.

5. How dark is the tint?

Tint darkness is measured by visible light transmission (VLT): the percentage of light the lens lets through. Lenses in the 18 to 43% range (Category 2 under the international standard) are a medium tint that works for everyday sun and changing light. Lenses in the 8 to 18% range (Category 3) are darker and suit intense sun at the beach, on the water or in the desert. Folds let through 19.7%, toward the darker end of the medium range. No sunglasses should be worn for driving at night.

6. How small does it really fold?

Some "folding" sunglasses only fold at the temples, like any regular pair. True folding frames also fold at the bridge, cutting the width in half. Check the folded size and the case: a slim case that fits a pocket is more useful than a hard case you will leave behind.

7. Fit

Folding frames vary in size, so compare the lens width (the first number in measurements like 51-20-140) with a pair you already own. Spring hinges give extra room for wider heads.

8. Warranty

Because folding sunglasses have more moving parts, the warranty tells you how much the brand trusts its hinges. Two years is good. Three is better.

The main options

• Folds ($49.95). Flexible TR90 frame with metal-core temples, polarized UV400 lenses, spring hinges, 19 g, vegan leather case, drawstring bag, cleaning cloth and mini screwdriver, 3 year warranty. One versatile square frame in black or tortoiseshell. Available on Amazon.
• Foldies (from $89). A well-established folding sunglasses brand with several frame styles, a prescription option, polarized CR-39 lenses with a darker Category 3 tint, and a two-year warranty. See Folds vs Foldies.
• Ray-Ban Folding Wayfarer (RB4105). The famous name and the classic Wayfarer shape, sold in both polarized and non-polarized versions at premium prices. See Folds vs Ray-Ban RB4105.
• Budget folding sunglasses. Plenty on Amazon for under $20. Some are fine as a backup; many skip polarization, use plastic hinge pins and come without a meaningful warranty.

The short version

Look for metal hinges, a flexible frame, polarized UV400 lenses that pass the FDA impact test, a slim case and a warranty of at least two years. That is exactly the brief we built Folds to. Get Folds on Amazon for $49.95.