REASONS TO BUY
Barely-there feel
Packs down flat
Fun color options
REASONS TO AVOID
Not-so-great sun protection
Only one size
REI Co-op On the Trail Cap Review
A fantastic airy cap for the trails or town that's big on comfort but light on sun protection
Credit: Lissette Velasquez
By Lissette Velasquez ⋅ Review Editor ⋅ October 30, 2026
RELATED: The Best Sun Hats of 2026
Our Verdict
If you're looking for a comfortable, breathable, affordable sun hat that keeps a low profile, the REI On the Trail Cap is one of our favorites. This thin, ultralight hat is made with soft, flexible materials that made it feel like we weren't even wearing a hat. Plus, it's ultra-packable, so it's easy to bring along for hiking, running, and sightseeing. Though it doesn't provide the best sun protection, it does a great job keeping the sun off your eyes and forehead, which may be all some users need. If you have an average- to large-sized head, we think you'll love the airy comfort of the REI On the Trail Cap.
Compare to Similar Products
 This Product
REI Co-op On the Trail Cap | |||||
|---|---|---|---|---|---|
| Awards |  Best Budget Sun Hat |  Best Beach Hat | | ||
| Price | $36 List Check Price at REI | $17.00 List Check Amazon (on sale!) | $40 List Check Price at Amazon | $14.00 List Check Price at Amazon | $32 List Check Price at REI |
Overall Score  |
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| Star Rating | |||||
| Bottom Line | Easy to wear and easy to pack, this affordable cap checks everything except coverage | One of our all-time favorite budget hats for everyday sun seekers | This wide-brimmed straw hat is comfortable, breathable, protective, and looks good too | A budget-friendly hat with great sun protection, but a heavy, rigid feel | The Bora Bora is one-size-fits-all and will stretch out after light use, though it does offer decent ventilation and is comfortable |
| Rating Categories | REI Co-op On the Tra... | Furtalk Bucket Wide... | Hemlock Lifeguard Straw | Einskey Classic | Columbia Bora Bora B... |
| Protection (35%) | |||||
| Comfort (30%) | |||||
| Breathability (25%) | |||||
| Packability (10%) | |||||
| Specifications | REI Co-op On the Tra... | Furtalk Bucket Wide... | Hemlock Lifeguard Straw | Einskey Classic | Columbia Bora Bora B... |
| UPF rating | 50+ | 50+ | 50+ | 50+ | 50 |
| Brim Size | 2.5" | 3.5" | 4.5" | 3.8" | 3.0" |
| Material | Body: 96% polyester, 4% elastic; Lining: 100% recycled polyester; Sweatband: 91% polyester, 9% spandex |
100% nylon | 100% straw | 100% polyester | Nylon, polyester mesh |
| Chinstrap | No | Yes | Yes | Yes | Yes |
| Packable/Compressible | Yes | Yes | No | Yes | Yes |
| Machine Washable | No | No | No | No | No |
| Ponytail Hole | Yes | Yes | No | No | No |
| Weight | 1.6 oz | 2.7 oz | 5.4 oz | 5.2 oz | 2.6 oz |
| Size Tested | One Size | One Size | One Size | One Size | O/S (6 1/2 - 7 1/2) |
Our Analysis and Test Results
We took this hat on sweaty trail runs, sunny high-elevation summits, and casual neighborhood strolls. The verdict? A cozy, lightweight, versatile cap that can keep up with just about anything. Credit: Lissette Velasquez
Likes
The REI Cap scored above average in both comfort and breathability. Though it didn't completely rock our socks off, its incredibly lightweight feel made it a worthy companion for active days in the sun.
The soft, thin, stretchy materials make it easy to wear all day and forget it's even there. Even the brim is flexible, so it never dug into our foreheads like traditional stiff ball caps. And while we wish it were available in more than one size, the bungee closure at the back ensured most average-to-large-sized heads could get a comfortable, snug fit.
With details like a flexible brim, the REI Trail Cap nails comfort and packability. Credit: Lissette Velasquez
The ultralightweight materials and open back also make the REI Cap one of the more breathable sun hats we tested. While running on the trails, we could always feel a nice, steady breeze across the sides and back of our heads.
If there was one thing we could improve, though, it would be better front ventilation so our foreheads could enjoy the same cooling effect during sweltering desert hikes.
The thin material is inherently breathable, but adding more perforations would take this hat's breathability to the next level. Credit: Lissette Velasquez
Another feature we love about the On The Trail Cap is how packable it is. We could toss it into our daypack without worry. And, in a pinch, we could fold the brim in half to fit it into a running vest pocket. It's a small detail that makes it easy to bring along, even when space is tight.
This hat packs down flat and takes up virtually no space. Credit: Lissette Velasquez
Dislikes
Unfortunately, the REI Caps' barely-there feel also means they don't block much sun.
The UPF 50+ material always kept our eyes and foreheads shielded from the sun's UV rays, but our noses, cheeks, and necks were left mostly exposed. That's no surprise, though, given the ball-cap styling. For more all-around shade, a wider brim that wraps around the whole head will provide better protection.
The REI Trail Cap will reliably keep the sun out of your eyes, but doesn't offer much coverage beyond that. Credit: Lissette Velasquez
In addition, while the REI On The Trail Cap is incredibly comfy, it only fits medium-to-large heads. Our small testers could get a snug fit, but the extra fabric rubbed on the ears and bunched up in the back. And for our extra-large testers, the flat, shallow crown made the hat look a little awkward.
On smaller heads, excess fabric can bunch above the cinch cord and rub against the ears. Credit: Lissette Velasquez
Should You Buy the REI On The Trail Cap?
If you have an average-to-large-shaped noggin and want a thin, lightweight, affordable hat for the trails and around town, the REI Trail Cap is a fantastic option. Although it's not the most breathable running cap we've tested, it breathes better than most classic sun hats and stays comfortable during active pursuits. And with color options ranging from standard black to flashy pride, it's easy to find a style that fits your vibe. It doesn't fit small heads, though, and isn't a great choice for someone who needs full sun protection.
The flat brim gives the REI a sporty, laid-back look that feels right at home on the trail or around town. Credit: Lissette Velasquez
What Other Sun Hats Should You Consider?
If you're looking for better coverage, consider the Sunday Afternoons Ultra Adventure Hat. This popular hat topped our charts in protection, comfort, breathability, and packability, making it a great all-around choice for athletic endeavors in the sun. Or, if you want something a little more flexible than the Ultra Adventure, we also like the Outdoor Research Sun Runner Cap. It provides maximum sun protection when you need it, and a casual ball cap style when you don't, for roughly the same price as the REI Trail Cap.
We think the Trail Cap (left) is plenty breathable, but for maximum, keep-you-cool airflow, look for a mesh-lined trail running hat (right). Credit: Lissette Velasquez
—Lissette Velasquez
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