When you're taking a hot beverage to go, you want your container to do two things: keep the beverage hot and not spill all over you. But which one is actually going to keep your coffee or tea from getting cold and unpleasant over the course of the day? There are dozens and dozens of options for your beverage-containment needs, so we decided to round up five of the most popular travel mugs and test how long each one kept hot water hot. 

For our experiment, we picked up the Contigo Stainless Steel Travel Mug, the Hydroflask Steel Travel Mug, the Yeti Vacuum Insulated Steel Bottle, the Zojirushi Travel Mug, and the classic Thermos Beverage Bottle. We tested the bottles over the course of two days. On the first day, we filled all the containers with hot water and took the temperature of the water over the course of the day to track how quickly they lost their heat. To account for the possible heat lost during the course of taking the temperature that frequently, we added in another round of tests. On day two, we again filled each container with hot water, let them sit for six hours, and checked the temperature.

Hydroflask Travel Coffee Mug (16 oz, $25)

Many people I know swear by the Hydroflask line to keep things cold or hot. (One friend of mine, a teacher, has multiple sizes of the flask for bringing in soup and coffee). But the Hydroflask (16 oz, $25) was, by a small margin, the worst at holding a steady temperature, dipping down to 122 degrees. It does, however, have a flip-up lid, which makes it an easier sell for people trying to drink coffee on the go. 

Contigo Autoseal West Loop Travel Mug (16 oz, $13)

The Contigo kept water at 127 degrees after 6 hours, a decent, if unremarkable, performance. But of the containers we tried, the Contigo was the most budget friendly, coming in under $15 for a mug that will easily keep your coffee hot enough to drink for a commute to the office. (Most of us, after all, can drink a 16 oz beverage in fewer than six hours). Of these three, the Contigo is best designed to drink coffee on the go without spilling all over yourself—a clever autoseal technology means that sipping is a fairly smooth process.

Yeti Rambler (18 oz, $30)

The Yeti Rambler (18 oz, $30) performed the best of the rest of the pack. After six hours, the water has cooled to 149 degrees, still very much drinkable warm coffee. Yeti doesn't offer a 16 oz option, so we went for the 18 oz, the closest to the other containers' capacity. It's definitely serviceable, but at $30, it's also on the more expensive end of all the mugs we tried. Plus, the design of the Yeti means that you have to unscrew the top before every sip—no big deal for carrying cold water on a hike but annoying for drinking coffee on the go. 

Zojirushi Travel Mug (16 oz, $25)

Of the travel containers we tested, the winners, far and away, were the Zojirushi Travel Mug and the Thermos Insulated Beverage Bottle). Both held their temperatures for an impressive length of time. The water we poured into the containers started at 185 degrees Fahrenheit—not quite boiling, but plenty hot. After six hours, the Thermos was still holding strong at 164 degrees, and the Zojirushi kept the liquid at a toasty 165 degrees. In our hourly temperature test, the Zojirushi only fared very slightly worse than the Thermos, dropping about 5 degrees per hour it was out. The Thermos only dropped an average of 3.5 degrees per hour. 

Thermos Insulated Beverage Bottle (16 oz, $20)

In terms of pure keeping liquids hot as long as possible, we'd recommend the Thermos. If you want to keep hot soup or coffee hot on a longer excursion, like a hike or a camping trip, go for the Thermos. However, if you're looking for something you could easily sip from as well as keeping the liquid warm, the Zojirushi's design makes that much more convenient—no unscrewing a lit and an inner seal like the Thermos. It's a bit pricier, but still well within reasonable range.