SOXAI Ring X could give Oura and RingConn something to think about

Japan has a smart ring brand worth keeping an eye on, and it is looking beyond its home market. SOXAI has launched its ultra-slim Ring X on Kickstarter, raising more than $750,000 in just a few days.

That’s a pretty strong start for a company most people outside Japan probably haven’t heard of. But SOXAI isn’t some unknown startup showing off a few renders. It has been making smart rings since 2022 and already has a sizeable customer base in Japan.

The company says its products have attracted around 80,000 users to date. Its technology has also appeared in other products, including the Sharp Karada Mate Ring we covered earlier this year. So there is a bit more history here than you might expect.

A smaller ring without sacrificing too much battery life

The main selling point is the size. SOXAI Ring X measures just 5.19mm across the band, making it considerably narrower than most established smart rings. The company claims this makes it the world’s narrowest smart ring with vital-sign tracking.

That’s a fairly specific claim, but the dimensions are impressive regardless. SOXAI also quotes a thickness of 2.6mm for the finished product, with a titanium alloy construction, 100-metre water resistance and three colour options: brushed silver, matte black and gold.

What’s more surprising is the battery life. Despite the smaller dimensions, SOXAI claims up to 10 days between charges. That’s competitive with plenty of larger alternatives, including some of the devices featured in our best smart rings guide.

There is a catch, though. That maximum battery figure applies to the larger US sizes 10 to 13, and smaller versions will offer shorter endurance. The company’s own comparison chart also includes another ring measuring 5.2mm wide, just 0.01mm wider than Ring X. So the combination of narrow dimensions and battery life is arguably more impressive than the record-breaking claim itself.

As for tracking, the familiar features are all here. Ring X uses optical sensors for heart rate, HRV and blood oxygen monitoring, alongside skin temperature and movement sensors. The companion app provides sleep stages, sleep scores, activity tracking, stress information, chronotype insights and sleep-apnea tendency monitoring.

There’s no mandatory subscription, either. SOXAI says all app features, including those introduced through future updates, will remain free. That puts it closer to the approach taken by RingConn than Oura.

The international launch is the bigger story

Perhaps the most noteworthy part of this announcement is that SOXAI is finally making a serious attempt to sell beyond Japan. Unlike many crowdfunding brands, it already has several generations of hardware behind it, with product development, manufacturing and testing handled in Japan.

The Kickstarter campaign opened on October 2 and runs until October 10. Early-bird pledges start at approximately $279, with standard pledges around $319. SOXAI is targeting a future retail price of $399, although the device hasn’t been sold at that price yet.

There is also quite a wait involved. Deliveries are currently scheduled between May and July 2027, with sizing kits expected to reach backers by December 2026. The company already has a functioning prototype, but final design validation and production testing are still to come.

International availability is not completely settled, either. According to SOXAI’s Kickstarter FAQ, the company plans to obtain the necessary certifications for markets including the US, UK, EU, Canada and Australia. Those approvals are not all in place yet, and customers in unsupported regions will receive refunds rather than devices.