- Hydro Flask has started selling $19 micro bottles that hold 6.7 ounces of liquid.
- Fans told Business Insider that the tiny containers are convenient for drinks like milk and matcha.
- They also said the online-only bottles are tough to purchase, with each restock selling out quickly.
How much water should you drink per day?
The answer varies, but it's always way more than six ounces.
So it's puzzling that Hydro Flask — one of the largest water bottle brands in the world — would start selling teeny tiny bottles that are smaller than the average iPhone.
Don't judge the micro bottles by their size, though. Some fans tell Business Insider that they might just be worth the hype.
The water bottle of the moment is extra tiny
Reusable water bottles are getting smaller.
Thin Owala bottles usurped Stanley tumblers in 2024, then shorter, thicker Bink bottles had a moment in 2025.
Hydro Flask has taken things a step further — or should I say, smaller.
The brand announced in late February that it was launching the $19 Micro Hydro: a 6.7-inch bottle made in collaboration with Hydro Flask Japan that holds just a few sips of your favorite drink.
That's about 10 ounces less than the average plastic water bottle, and 25 ounces less than the trendy but bulky tumblers that have become standard.
The online-only launch quickly sold out, leading to the brand releasing new colorways in late March. That inventory didn't last a day in its online store, and the product hasn't been restocked.
Currently, Micro Hydro Flasks are only available on resale websites for between $50 and $100 each.
Heidi Ng, a 32-year-old from San Francisco, is a self-described "water bottle girl." She's tried options from Stanley, Hydro Flask, and Yeti, and even follows the brands on social media.
That's where she first encountered Micro Hydro Flasks, which she said instantly reminded her of the small water bottles she regularly saw people carrying during her past travels in China.
"It's only here in America that we've popularized 40-ounce bottles," she said. "When I'd visit relatives in Hong Kong, I'd bring my reusable bottle. They would laugh and say: Isn't that heavy? Why do you want to carry that?"
"So I wasn't totally surprised by the size, as maybe some people are," she added.
Cute, convenient, and controversial
Not everyone understands the product.
On Instagram, some Hydro Flask shoppers have asked why anyone would buy such a small bottle.
In most responses, water wasn't mentioned. Instead, people said they've used their micro bottles to measure small pre-workout drinks, to keep soup hot, and as flasks for alcohol.
Then there's Haley Carter, 28, from Tennessee. She told BI that she's used her micro bottle as "an emergency milk stash" to keep the drink cold for her 1- and 3-year-old children on the go.
Geneveive Kelley, a 25-year-old from California, told BI she uses her micro bottle "for everything" — but she especially loves using it to carry matcha.
"I have to have a little sweet drink or something like that each day," Kelley said. "So sometimes, I'll put some matcha that I already made…so I can have it later."
When some fans use the small product to carry water, they're using it because of its convenience.
"It fits in pretty much every single purse that I have, and it fits in my jacket pockets," Ng said. "It actually can be really useful if I'm going out to brunch or somewhere I don't want to carry a full water bottle, and we're walking and talking and I suddenly need a sip."
Kelley, a big Disney fan, said it's also helped her stay hydrated at Disneyland.
"I hate bringing anything heavy into the park," she told BI. "I wanted something light, and because they have refill stations everywhere, [the Micro Hydro Flask] is really convenient."
Micro Hydro Flasks are accessories, not necessities
When Hydro Flask restocked its micro bottles in March, Ng said that buying them was like "getting concert tickets." She waited in line for 25 minutes to get the item, and at the checkout page, she said her payment wouldn't go through. It just kept processing — a common complaint from people who tried to purchase the micro bottles.
While Ng was lucky enough to secure her purchase eventually, countless fans have shared online that they never made it past that page. The number of people trying to buy the same bottles was just too high.
What all three women — and other shoppers who have posted about the bottle on social media — agree on is that Micro Hydro Flasks aren't necessities. They're just convenient and cute hydration tools.
"People think that I'm replacing my 32-ounce Hydro Flask with a 6.7 Micro Hydro as my form of hydration. That's not happening," Kelley said. "I'm still drinking my normal intake of water. I just happen to have a little accessory that goes with me everywhere."
