SOXAI RING X is not yet available in your region. The Limited Price Pass is only available in the countries we currently support, but feel free to look around.
SOXAI RING X, the world’s smallest smart ring, is live on Kickstarter. The campaign ends October 10, 2026, 11:59 PM JST.
Back SOXAI RING X on Kickstarter

Campaign ends October 10, 11:59 PM JST.

NOW LIVE

SOXAI RING X is
live on Kickstarter.SOXAI RING X is
live on Kickstarter.

Our newest smart ring, SOXAI RING X, is now taking pledges on Kickstarter. The campaign ends on October 10, 2026, at 11:59 PM JST.

Back it on Kickstarter

About the Limited Price Pass

SOXAI RING X project image on Kickstarter

Pass sales have closed. If you bought a pass, check your inbox: we’ve emailed you a link to back SOXAI RING X at the pass-holder price.

Can’t find the email? Contact us and we’ll help.

ABOUT SOXAI

From SOXAI, Japan’s smart ring brand.

SOXAI RING X is developed, engineered, manufactured and tested in Japan, and after-sales support comes directly from our own team. It is, in every sense, made in Japan.

80,000+ cumulative users
Japan’s No. 1 smart ring app downloads

**Cumulative downloads of smart-ring apps in Japan, Jan 2022–Dec 2024 (App Store and Google Play combined; SOXAI research).

SOXAI RING 2 on display at a major electronics retailer in Japan
On sale at major electronics retailers across Japan.

OUR TRACK RECORD

Three times, the world’s smallest ring.
SOXAI RING X makes it four. Three times, the world’s smallest ring.
SOXAI RING X makes it four.

Since 2022 we’ve designed, manufactured and shipped four generations of smart rings, all in Japan. Three were the world’s smallest at launch.*

  1. SOXAI RING 0

    World’s smallest *

    Crowdfunded for about US$290,000. The world’s first smart ring made in Japan.

    The SOXAI RING 0 crowdfunding page, showing the campaign fully funded.

  2. On general sale

    On general sale in our own store.

    SOXAI RING 0.

  3. SOXAI RING 1

    World’s smallest *

    The second generation.

    SOXAI RING 1.

  4. SOXAI RING 1.1

    Third generation. Longer battery, steadier connection.

    SOXAI RING 1.1.

  5. SOXAI RING 2

    World’s smallest *

    Fourth generation. Also the longest battery in its class.*

    SOXAI RING 2, shown in five finishes.

  6. SOXAI RING X

    World’s smallest *Live now

    Fifth generation. Live on Kickstarter now.

    SOXAI RING X, with its 5.19 mm ring width called out.

*Based on publicly available information from major smart ring manufacturers (SOXAI research). Claims for released products refer to the time of release; the claim for SOXAI RING X reflects information as of August 2026. For SOXAI RING 2, the comparison is among smart rings rated for four days or more of battery life.

Forget you’re wearing it.
That’s the only spec that matters.

Smart rings keep getting smarter. Along the way, we went back to a simpler question: what makes a ring you’ll actually keep on? Nothing else counts if you take it off. SOXAI RING X is 5.19mm wide, the world’s smallest*, small enough that you stop noticing it, with up to 10 days on a charge.

Ring width

World’s smallest* 5.19mm

Max battery
life

10days

*Based on publicly available information from major manufacturers of vital-sensing smart rings (SOXAI research, as of August 2026).

SIZE × BATTERY

“Smaller ring, shorter battery.”
Physics, they said.

Until now, every smart ring asked you to choose. Shrink the ring and you lose battery life. Stretch the battery and the ring gets bulky. Plot every ring on the market and the pattern draws itself. A hard diagonal runs through the field, and nothing crosses it. We call it the size-battery barrier. The industry treated it as a given. SOXAI RING X ends it.

Ring width vs. max battery life. SOXAI RING X achieves 5.19 mm and 7–10 days, above the trend of existing products.Ring width vs. max battery life. SOXAI RING X achieves 5.19 mm and 7–10 days, above the trend of existing products.
Smart ringRing widthMax battery life
SOXAI RING X5.19 mm10 days
Company V5.2 mm3 days
Company O6.09 mm9 days
SOXAI RING 26.7 mm15 days
Company R6.8 mm14 days
Company S7.0 mm7 days
Company C7.8 mm8 days

*Based on publicly available information from major manufacturers of vital-sensing smart rings (SOXAI research, as of August 2026). Battery figures are each manufacturer’s stated maximum.

Asleep or awake,
watching over you 24/7 With the free companion app. No subscription.

Sleep score, sleep stages, steps and stress — plus heart rate, HRV, blood oxygen (SpO2), sleep-apnea tendencies, chronotype and more, all recorded and analyzed. See how you change day to day, and use what you learn to stay on top of your condition.
*Specifications are in development and subject to change.

App screen: sleep score
Sleep scoreSee last night’s sleep quality at a glance.
App screen: sleep stages
Sleep stagesHow deep you slept, and for how long.
App screen: steps
StepsDaily steps, tracked automatically.
App screen: stress monitor
Stress monitorSee how tense or recovered your body is.

FAQ

Frequently asked questions

Yes. You can back it on Kickstarter until October 10, 2026, 11:59 PM JST.
No, pass sales have closed. You don’t need a pass to back the campaign: anyone can pledge on Kickstarter.
A Kickstarter account and a credit card. Your card is charged when the campaign ends.
We expect to deliver between May and July 2027. The latest schedule is on our Kickstarter page.
We’ve emailed instructions to the address you used at checkout. Use the link in that email to pledge at the pass-holder price in a web browser. The pass-holder price isn’t available in the Kickstarter app.
Yes. SOXAI RING X delivered to Kickstarter backers will come with the companion app in English, and you can select English in the app’s language settings. Support for languages other than English has not been decided yet. We’ll announce it once it is confirmed.
Our Kickstarter page lists the countries where we’re getting SOXAI RING X certified. If we can’t get it certified for your country, we won’t ship it there and will refund your pledge in full.

SOXAI RING X
is live on Kickstarter.

Back SOXAI RING X on Kickstarter

Campaign ends October 10, 11:59 PM JST.

Back it on Kickstarter

Campaign ends October 10, 11:59 PM JST.