Everybody needs to carry water with them while hiking. Hydration is one of the Ten Essentials that you always need when you hike, and one way to make sure you stay hydrated is by carrying a water bottle and drinking from it regularly.

Reusable water bottles are a multi-billion dollar market, expected to reach $11.5 billion by 2027. While there are lots of stylish water bottles out there, not all of them are great for hiking. If you’re wondering how to choose a water bottle for hiking, here is a complete guide to everything you need to know about hiking water bottles.

Water bottles come in several different styles and materials.

Choosing a water bottle isn’t just about capacity– although that is important. You need to consider the whole water bottle and how it will function when you take it out hiking.

Each type of water bottle construction has its pros and cons. While all of these can be good options for hiking, each material has characteristics that determine how useful it will be for you.

The capacity and weight of your water bottle will vary widely depending on the style of bottle and its capacity. For example, the Nalgene Ultralite Wide Mouth bottle and Klean Kanteen TKWide Recycled Insulated bottle contain the same amount of water– but the Kleen Kanteen weighs more than 5 times as much as the Nalgene bottle!

If you want to use the water you bring with you for cooking, or just want to measure how much you’re drinking over the course of a day, some water bottles have markings on the side that show you exactly how much you’ve had and how much you have left. For example, Nalgene has measure marks for both milliliters and fluid ounces, making them great for keeping track.

For many hikers, part of enjoying the outdoors is choosing gear that supports sustainable resource use. One of our biggest polluters is bottled water. Bottled water has an environmental impact 3,500 times greater than tap water, and only about 30% of all recyclable plastic water bottles actually get recycled. This puts millions of pounds of plastic waste into our oceans and landfills every year, and is part of the reason that the reusable water bottle industry has become so large. It’s just as convenient to carry a reusable bottle.

When you’re choosing a water bottle, look for one that uses post-consumer or recycled materials. It’s also much more sustainable to choose a bottle manufactured in the United States; this means that less fuel is used transporting it across the ocean. One of the most popular hiking water bottle brands, Nalgene, makes their bottles in Rochester, NY using as much recycled plastic as possible, making them a more sustainable choice than many other plastic alternatives.

Water bottles and hydration bladders are both popular ways to carry water while hiking. Many hikers like to carry both, starting out with a full hydration bladder and carrying extra water as a backup.

Not sure which to carry? Here’s the key differences between the two.

In most circumstances, you can freely choose between either or both. If you’re day hiking, you probably just need a water bottle or two. Choose based on your activity and how much water you’re comfortable carrying with you!

If you’re a mountaineer or like to hike at high elevation, you should be aware of pressure changes and what they can do to your water bottle. If you have a vacuum bottle that has a full-screw on lid, the pressure change at high elevations could make it impossible or very difficult to open. If you plan on climbing a lot of elevation, make sure you have a quarter-turn opening, a pop-up straw, or some other way to release the pressure.

If you’re thru-hiking, backpacking, trekking, or other style of hiking where you don’t have frequent access to treated, clean water, you might not be able to take all the water you need with you. In that case, you don’t have to find a two-gallon tankard of a water bottle; you should instead choose a water filter or purifier and get used to the idea of drinking from natural water sources.

Long-distance hikers also tend to appreciate a water bottle with a high capacity to weight ratio. The lightest bottle on our list is also the largest, the Platypus Platy 2.0. If you’re looking for a bottle for long-distance hiking, be sure to check that one out.

If you carry a plastic bottle,  you may be worried about BPA. As we mentioned earlier, BPA is used in the manufacture of some plastics. The FDA maintains that BPA can safely be used in product packaging, but the safe dose for humans is still debatable. Even the most modern studies can’t agree on BPA’s risk or safety, and its long-term effects are still unknown.

Because of this, many hikers prefer to have a water bottle that can’t leach BPA into their drink. The easiest way to determine if your water bottle is truly BPA-free is to turn it upside down and look at its identification code. Plastic bottles labeled 1, 2, 4, and 5 are BPA-free. Plastic bottles labeled with 3, 6, and 7 are not.

So how do the best of the best compare to each other? Here’s a quick guide to the water bottles we’re featuring here.

These water bottles all weigh less than 4 ounces– perfect for ultralight backpackers or anybody who wants to save weight.

Nalgene’s ultra-light bottles use HDPE, a type of plastic that is extremely lightweight. These bottles are tough and durable, and while they don’t quite have that classic Nalgene aesthetic, they’ll carry your water and get the job done.

At a mere 1.3 ounces, the Platypus Platy 2.0 is the lightest bottle on our list. This feather-light bottle has a massive 70 ounce (2 liter) capacity and has become very popular with thru-hikers who want to maximize capacity while minimizing the weight and space their water bottles take up.

These water bottles are our favorite double-walled steel water bottles. They’ll keep your hot drinks hot and your cold drinks cold!

This insulated bottle is rated to keep hot drinks hot for 12 hours and cold drinks cold for 24 hours, and it lives up to this promise.

First rising to fame for their coolers, Yeti’s water bottles are tough, durable, and have exceptional insulation. The downside is the weight; these bottles are very heavy.

These water bottles will crush down, fold, or roll to a tiny size in your pack. If you want to save space, these are the bottles for you.

This water bottle collapses to a size that can fit in your pocket. We especially like the integrated strap that keeps it contained once you roll it up.

While the Flux doesn’t collapse quite as small as the Stow, this collapsible offering from HydraPak is one of the easiest collapsible water bottles to use. The material offers a really good grip, and you don’t have to worry about it collapsing as you fill it.

You could drop these water bottles down the side of a mountain and they’d come away fine. These ultra-durable bottles can take anything you throw at them (or throw throw at).

These bottles are everywhere, and for good reason. Lightweight and made from durable and recycled Tritan plastic, their ease of use, light weight, and good capacity have made them a favorite of hikers for decades.

This double-walled insulated water bottle has a twist cap with an optional stainless steel straw. It has a well-designed cap with few failure points, and its impact base cap makes it dent and chip resistant.

Don’t want to worry about spills? These water bottles make it easy to drink without stopping.

One of the most frustrating things about many water bottles with integrated straws is that the straw won’t let you drink all of the water. Not true with the CamelBak Eddy+; the straw is one of our favorite things about it. It’s well-designed and easy to drink from.

This relative newcomer to the water bottle market has quickly risen in popularity thanks to an innovative cap design that lets you choose between a straw or standard water bottle opening.

If you want a built-in filter, these bottles are just what you need.

This soft-sided, lightweight filtration system is packable and durable enough for all of your adventures.

LifeStraw’s straw-based water filters work just as well with an integrated bottle. Their filters are known for their ease of use and efficacy– you don’t have to worry about parasites, bacteria, debris, or even microplastics.

How does your favorite water bottle compare to the ones on our list? The next time you’re in the market for a new water bottle for hiking, be sure to check our recommendations to find the perfect bottle for you.