The biggest bottle isn't the best one. Size matters most: big enough that you're not hunting for refills, small enough to carry all day. For most trips that's a 24 oz insulated bottle like the Hydro Flask Wide Mouth with a straw lid.
Our picks
Hydro Flask 24 oz Wide Mouth Bottle with Flex Straw Cap
A 24 oz insulated bottle with a straw lid that keeps water cold all day and lets you sip one-handed on road trips and city days.
Hydro Flask 18 oz Standard Mouth Bottle with Flex Cap
A compact 18 oz insulated bottle that actually fits a daypack side pocket, cold water or hot coffee on city days.
Hydro Flask 32 oz Travel Bottle with Flex Straw Cap
A 32 oz insulated bottle with a cupholder-friendly base, a full day of water for the car or a long flight.
Nalgene 32 oz Wide Mouth Bottle
A light, leak-proof 32 oz Tritan bottle for hikes and road trips that also pairs with many water filters.
Nalgene 32 oz Narrow Mouth Bottle (Amethyst)
The narrow-mouth Nalgene, for hikers who drink while walking and want fewer spills.
Hydro Flask Flex Straw Cap (Standard Mouth)
A straw lid that turns a standard-mouth Hydro Flask into a one-handed sipper on flights and buses, cold drinks only.
KMN Straw Lid for Hydro Flask Wide Mouth
Fits 32 and 40 oz wide-mouth Hydro Flasks for the car or desk, but with few reviews we'd skip it if a leak in your bag would hurt.
RAYMYLO 64 oz Insulated Water Bottle
A half-gallon insulated bottle that's fine next to the car, but too big and heavy for a carry-on or daypack.
What makes a good travel water bottle?
Decide on insulation first. Double-wall stainless bottles like the Hydro Flask are rated to keep water cold for 24 hours, which you'll want on hot city days and road trips. Tritan bottles like the Nalgene aren't insulated, but they're lighter and tough.
Then the lid. A straw cap means one-handed sipping on planes and buses. A plain screw cap is easier to clean on the road.
What size water bottle is best for travel?
18 oz fits a daypack side pocket and works for city days with plenty of places to refill. 24 oz is the everyday size. 32 oz covers a full day of hiking or driving, but you'll feel the weight.
If it's hot, go bigger. A small bottle means stopping to refill all day.
Wide mouth or narrow mouth?
Wide mouths are easier to fill, clean and load with ice, and many pair with water filters. Narrow mouths are easier to drink from while you walk, with fewer splashes. For most trips we'd go wide.
Which water bottle features aren't worth it?
A half-gallon bottle sounds smart until you carry it. It's too big and heavy for a carry-on or daypack on most trips, so keep it for car camping and beach days.
Cheap third-party lids are tempting. With few reviews, though, it's hard to know if one will leak inside your bag. Buy the lid with the longer track record.
Questions people ask
Can I bring a water bottle through airport security?
Yes, at US and most other airports, as long as it's empty. Fill it at a fountain or refill station once you're through.
Is an insulated water bottle worth it for travel?
If you want cold water all day in hot weather or on road trips, yes. If you count every ounce, a light plastic bottle with a screw cap is simpler.
What size water bottle is best for travel?
24 oz is the everyday size for most trips. Go to 32 oz for hikes and road trips, or 18 oz if you carry a small bag.
Are Nalgene bottles good for travel?
Yes, for hikes and road trips. They're tough, light and leak-proof. They just aren't insulated.
Prices change often — the price on the retailer’s page is the one you pay.