This school banned cellphones 4 years ago. Here's how it's going — and why others are now following suit.

Girl sitting on floor looking at phone held in lap with back against row of multi-colored school lockers.
San Mateo High School banned cellphones in 2019 — and officials say it's been a success. (Getty Images)

In 2019, San Mateo High School, just south of San Francisco, became the largest school in the United States to become a cellphone-free environment. Now, nearly five years into what began as an experiment, the school considers the change an ongoing success.

“Students are actually talking to one another,” shares Yvonne Shiu, who has been San Mateo’s principal for 17 years. “We've had other people on our campus notice, like, ‘Oh my gosh, you can actually see students’ faces and eyes as they’re walking in the hallways and not looking down at their phones.’”

Shiu remembers clearly what a typical scene on campus looked like before the phone ban was put into place. “Students would sit in circles gathered with friends and they’d all be on their phones texting one another," she tells Yahoo Life.

In 2019 San Mateo made a massive change, implementing a policy that made it against the rules for students to use phones during the school day. They enforce the policy with a tool called Yondr, a locking pouch in which students place their phones upon arrival on campus; they are only able to reopen them again once the school day is over. Every day starts with kids placing their phones inside a Yondr pouch, which locks upon closure and can only be opened with a special Yondr unlocking base. The pouches go on desks, and as teachers circle the room collecting homework, they make sure all students have successfully “Yondred” as well. The devices are rising rapidly in popularity; Yondr recently told CBS they saw a 150% increase in schools using their pouches in 2023.

Shiu notes that banning phones has helped with online bullying, and the only con to her mind is that students have figured out how to break the Yondrs and get access to their phones. But when they do, their guilt usually causes them to “stick out like a sore thumb,” she says with a laugh.

San Mateo’s change is part of a larger movement to make schools cellphone-free spaces. Schools and districts from Missouri to Pennsylvania to Florida are making the change, with some extending the ban to smartwatches. And UNESCO has called for schools globally to ban phone use, in a measure they say would curb disruption and cheating, lessen cyberbullying and improve learning. Fewer than one in four countries have laws or policies in place restricting phone use in their nation’s schools, among them France and Rwanda.

In the 2023 school year, public schools in Montgomery, Ala., began implementing a cellphone ban. At Brewbaker Tech Magnet High School, assistant principal Robert Price says he’s already noticed some positive changes among the student body. “We’re seeing a lot more interpersonal interaction between the kids,” he notes. “I think that’s one of the things we’re happiest about, seeing them interact as kids.”

In addition to it leading to more socializing among students, Price says, teachers are happier to have one less distraction to compete with in classrooms. “A phone is a huge distraction,” he tells Yahoo Life. “If a child wants to sit there and watch a video, it’s going to affect their brains, it’s going to affect the instruction, it’s going to create a discipline issue. We’re just glad we’re not having to address those things the way we have in the past.”

All that said, the policy of banning phones remains somewhat controversial. Meryl Alper is an associate professor in the Department of Communication Studies at Northeastern University whose work focuses on social and emotional implications of communication technology. She's of the mindset that cellphone bans have not been proven to be a total positive. Alper notes that not having access to one’s phone is a policy harshest on students who may need access for work or family responsibilities. “I think about students who may be balancing things like child care or jobs outside of school, and in the U.S. that is more likely to be low-income Black and Latino students. So how might bans disproportionately impact them? Banning the phones in school doesn’t change the structural conditions outside of school,” Alper says.

Alper also believes that banning the phone is not necessarily the cure-all it’s sometimes thought to be. “Is the cellphone — removing it from a classroom, having kids lock them up before school starts and getting them back before the school day ends — is that in itself the most important contributor to what improves grades, what reduces bullying? I don’t think we have the evidence,” she tells Yahoo Life. Places where she believes energy should be put instead include better mental health support services for students and better parent outreach, digital citizenship and gun control.

“There is a real irony, in the U.S. context, between cellphone bans and assault weapon bans. The whole reason that kids might need phones in schools is to alert their parents of a school shooting or lockdown,” Alper says. “If we were really so concerned about children’s well-being in schools and paying attention and not being stressed, wouldn’t we be doing more about the access that young people, and others, have to assault rifles?”

At San Mateo, school shootings were the primary reason why parents did not initially support the change. The school’s phone ban was a grassroots effort that began with a few teachers volunteering to pilot the program in their classrooms. Full faculty buy-in came next, followed by convincing parents. “There was some pushback about being able to contact their student if there was an emergency — especially school shootings, and being able to contact their student and know what’s going on,” Shiu shares. She mentioned the school’s counterargument was that if an emergency like that were to occur, the distraction of the phone could be even more harmful. “We don’t want your students distracted trying to answer a text that you are sending them when we’re trying to give them instructions on following school safety procedures.”

According to Shiu, the San Mateo students are, for the most part, used to their phone-free environment by now. The same is true of their daily Yondr pouch checks — though some students have tried to cheat the system. "We have had students put a granola bar in their [Yondr] or a calculator or even a potato [instead of their phone],” she says. But by and large the students have embraced the policy. Shiu notes that feeder schools and districts near San Mateo have begun implementing their own cellphone bans, which makes the process even easier once the students reach high school.

“I know it can be daunting to take that leap,” Shiu says of implementing a phone ban. “I just wish other schools did consider it because the pros definitely outweigh the cons.”