Every traveler or outdoor enthusiast has been there. You reach your destination with your big, heavy luggage or backpacking rig, but you just want to head out for a quick stroll, a grocery run, or a casual afternoon of fishing without hauling the “big house” on your back. That is exactly where a packable daypack comes into play.
Today, I am diving deep into the Osprey Ultralight Collapsible Stuff Pack. I have been putting this 18L bag through its paces to see if it lives up to the Osprey reputation for quality while maintaining its “ultralight” status.
First Impressions and Portability
When you first see this pack, it is hard to believe it actually holds 18 liters of gear. It arrived in a tiny, compressed pouch that fits easily in the palm of my hand. This is the ultimate “just in case” bag. Whether you are traveling through an airport or heading to a trailhead, it takes up almost zero space in your main luggage.
The material is incredibly thin, which is how they keep the weight so low. While it feels delicate, the ripstop nylon is designed to handle the basics of daily use. Opening it up is like watching a magic trick. You simply unzip the small storage pouch and the entire backpack unfolds from within itself.
Layout and Organization
For an ultralight bag, the organization is surprisingly thoughtful. You get a spacious main compartment that handles most of your bulkier items. I found it perfectly sized for a lightweight raincoat, some snacks, and my basic fishing tackle.
There is also a second, smaller pocket towards the top. This is where I kept my smaller essentials. Inside this pocket, Osprey included a keychain holder, which is a life-saver when you are staying in a rental or hotel and do not want to go digging for your keys at the bottom of a dark bag.
One feature I was really happy to see was the dual water bottle holders. These sit on the sides and are made of an expandable mesh. They held my standard bottles securely, which is something many other packable bags skip to save weight.
Comfort and the “Whistle” Test
When you look at the back of the bag, you will notice the shoulder straps are quite thin. They are made of a very breathable mesh material that helps with airflow on those warmer days. Even though they are thin, I found them to be quite comfortable for light loads.
The straps are adjustable, and there is a neat little safety feature built right into the sternum strap: a whistle. It is a small detail, but if you ever find yourself needing to get someone’s attention in the woods, you will be glad it is there.
A Day on the Water
I recently took this pack out for a quick fishing session. I wanted something that wouldn’t weigh me down while I moved along the bank. It was the perfect companion for a few hours of casting. While out there, I actually managed to catch a small spotted bass. The bag stayed out of the way while I was moving, and I barely felt it on my shoulders.
The Trade-Off: Durability Concerns
As much as I like the portability of this pack, there are some things you need to keep in mind before buying. Because the material is so thin, I do worry about its long-term durability if you are hard on your gear.
I would be very careful about walking through thick brush where a tree branch might snag the fabric. I also would not recommend sitting this bag down on sharp rocks or putting heavy, sharp-edged tools inside without some protection. In my opinion, this is not a heavy-duty hiking pack. It is designed for travel, light walks, or carrying your raincoat and some groceries around town.
Watching the Video Review
If you want to see exactly how this bag folds up and how it looks when I am wearing it, I put together a full video review on my YouTube channel. You can check that out right here:
Where to Buy
I purchased my Osprey Stuff Pack from Amazon, and it has been a solid addition to my gear closet. While mine is the classic black, they actually offer several different color variations on Amazon if you want something that stands out a bit more.
Check out the Osprey Ultralight Collapsible Stuff Pack and color options here
Final Thoughts
The Osprey Ultralight Collapsible 18L Stuff Pack is a specialized tool. If you need a rugged mountain bag to haul 30 pounds of gear, this isn’t it. But if you want a high-quality, lightweight, and incredibly portable bag for travel or casual outings, it is hard to beat. It fits into your life without taking up space, and the 18L capacity is the “Goldilocks” size for most day trips.
