REI Flash 18L Review

Last Updated on February 20, 2018 by foxintheforest

Gear. You have to have the right tool for the job in the backckountry. In part two of my three-part series of micro-gear reivews, I’m talking about one of my favorite finds: the REI Flashpack 18L. This little slack pack is small but mighty. Read my REI Flashpack 18L review to find out why.

Read part of the series: Sea to Summit Ultra-Sil Compression Dry Sack.

Why the REI Flash 18L?

Recently I’ve gotten into slack packing peaks. This is where you backpack into a location, sleep, and hit a peak the next morning. This is where my trusty old Camelback pack fell short. I need something light, compact, and functional on class 3 and class 4 terrain.

REI Flash 18L Review

How I Tested the REI Flash 18L

Since I bought it, I’ve used this thing in every conceivable situation I can come up with. I used it to slack pack up East Thorne in the Gore Range, taken it on day hikes, road trips, plane rides, beach days, car camping weekends, you name it.

How the REI Flash 18L Performed

I love this little pack. It’s durable, lightweight, and has the basic features any daypack should have. It’ll carry my MacBook Air, puffy layer, and even does a decent job with a climbing helmet. Although the REI Flash 18L is minimal, it’s surprisingly comfortable. A great find for a quick day adventure.

A few features include a small zip front pocket for stashing snacks and sunscreen, a couple of small interior pockets, and a handy key clip. The pack also has a built-in whistle, hydration pack sleeve, small pad, axe carry and a minimal, removable hip belt. The loops down the middle allow you to strap on some extras such as a helmet or doggy water bowl.

REI Flash Review

Scrambling to high places with my REI Flahs 18.

The REI Flashpack 18L packs down into a backpacking bag like a charm. It is the ideal companion for those who are backpacking and want something smaller for nearby excursions. The pack performed well descending rock and made a good scrambling companion.

For travel, it’s slightly annoying compared to a purse a shoulder bag, but a great addition for someone who wants a small pack that would fit inside a carry-on without taking up a noticeable amount of space.

This pack also has the added bonus of coming in some fun prints for no extra cost. It’s nice to have something with a little flair on the trial. Overall, the REI Flash 18L is one of my top gear purchases of the summer.

Best Uses

  • Slack Packing Peaks
  • Scrambling Peaks
  • Quick and Easy Dayhikes
  • Lightweight Travel Pack
  • A Day at the Beach


Since this is a stripped-down, ultra-lightweight day pack bells and whistles are limited. Pole carry is impossible and ice axe carry is possible, but a little flimsy. This pack could be improved with a few extra features such as a small, elastic side pouch to put a small snack or stash a bladder mouthpiece.

REI Flash 18L in action

So nice we bought it twice. Squirrel scrambling on some class 4, lower class 5 rock with his REI Flash 18


For only $39.95 this pack is extremely reasonable. Comparable bags by Osprey and others retail at nearly double the cost. If you’re looking for a snappy little daypack, definitely give the REI Flash 18 a whirl.

The Verdict

For a slack pack the REI 18L offers to most bang for your buck. It isn’t meant for long, complicated outings. But for a grab and go bag or a backpacking daypack it’s the perfect companion.

REI Flash 18L might just be the most versatile daypack out there for the price. It's durable, compact, and ready for adventure. Perfect for travel, slack packing, or small day hikes. REI Flash 18L Review | daypack review | hiking pack review | travel pack review


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Meg Atteberry

Meg is a long-time Colorado local and outdoor industry professional. She's spent the last 15 years hiking, climbing, mountaineering, and canyoneering all over Colorado, Utah, Arizona, and Nevada in search of the best views. She's written for Outside Magazine, REI, Backpacker Magazine, and appeared on the Weather Channel.

Hi There!

Meg Atteberry standing on a mountain sticking her tongue out

Meg aka Fox is a 30-something who's born to explore. Toddler mom, queer, and neuro-spicy her favorite things to do are climb in the alpine and camp in the desert. Her mission is to get you out on your greatest adventure.