The short answer
You hold an O2 or Three contract and a ticket to Tokyo, and the choice is whether to roam or buy a travel eSIM first. I compared what each carrier charges in Japan, read on 31 October 2026, with the travel eSIMs I priced on 10 November 2026 and with Ringo Light. For a trip past a day or two I would buy Ringo Light and keep my own SIM in for calls and texts.
Unlimited data at full speed for 2 weeks at $21.99 or 30 days at $54.99, nothing renews. Airalo asks $48 for 15 days and $69 for the month, and daily roaming charges climb past both.
For light use on maps and train apps: 10 GB for 30 days at $16, 20 GB at $23, and 3 days of unlimited at $11, on KDDI au and SoftBank.
One of the few brands on NTT Docomo, Japan's largest network, with KDDI. 10 GB for 30 days at $16.50.
Days, not gigabytes, on KDDI and SoftBank, with no daily cap to count. $27.50 for a week, and sharing is limited to 1 GB a day.
Prices read on 10 November 2026: Airalo, Holafly, Saily, Nomad, Ubigi, O2, Ringo Light, European Central Bank, Three on their own sites or listings, Ringo Light from its catalogue. All in US dollars unless stated. Treat every number as a snapshot.
See the full price index for every country.
Travelling further? Compare the best eSIM for Asia and the eSIM for Asia-Pacific.
The prices, charted
US dollars, 10 November 2026. Ringo Light sells 14 days, the others 15. Nomad's unlimited now stops at 10 days. Ubigi's 15 days is 30 GB at full speed, then 2 Mbps.
The 30-day plan at each brand. Ringo Light is unlimited data at full speed. Ubigi's month is 60 GB at full speed, then 2 Mbps. Nomad stops at 10 days.
Holafly sells no buckets. Ringo Light sells no bucket either: its 2 weeks is unlimited, and lasts 2 weeks, not 30 days.
Side by side
Swipe to compare →
Get Ringo Light for Japan, from $9.99.
Installed once, next to your own SIM. Your eSIM arrives by email in seconds.
- 3 days $9.99
- 2 weeks $21.99
- 30 days $54.99
We sell data eSIMs for now to fund the full Ringo service. Ringo is self funded. Every plan bought here pays for the build of one plan that works everywhere.
Want to keep your own number abroad?
That is the full Ringo service: one plan that works everywhere, with your own number included.
It is a separate product from Ringo Light and it is still being built, so it is not on sale yet. Join the waitlist to hear when it opens.
What to see in Japan, and what your phone needs for it
Eight places most trips to Japan include, from Tokyo and Mount Fuji to Kyoto, Osaka and Hiroshima. Whichever plan you pick, the tip under each one is where your phone matters.
Roam with your carrier, or buy an eSIM
O2 Travel works in Japan at £7 a day, about $9, charged only for days of use, and each charge covers 24 hours from first use. At the ECB reference rate of 30 October 2026, £1 = $1.34, three days is £21 (about $28), two weeks £98 (about $131) and a month £210 (about $281). Three lists Japan in Go Roam Around the World Extra, at £8 a day (about $11) on plans joined on or after 18 December 2025 and £7 on earlier ones. Passes bought in advance are £17.50 for 3 days, £29.75 for 5 days, £42 for 7 days and £84 for 14 days, about $113. Daily charges come to about $32 for three days, about $150 for two weeks and about $322 for thirty days. I read all of it on 31 October 2026.
Ringo Light is one payment per trip: $9.99 for 3 days, $21.99 for 2 weeks and $54.99 for 30 days. Two weeks in Japan is about $131 on O2 Travel, about $113 on Three's 14-day pass and about $150 on Three's daily charge, against $21.99 on Ringo Light, and a long weekend is about $28 on O2 against $9.99.
Among the travel eSIMs, Ringo Light is also the cheapest unlimited for two weeks and a month. Ubigi asks $39 for 15 days, Airalo $48, Saily $48.99 and Holafly $50.50, Nomad's unlimited stops at 10 days at $33, and for a month the rivals run $65 to $73.90. For 3 days Nomad charges $11 against $9.99.
What O2 and Three win is real, and I do not wave it away. Your UK number keeps ringing, calls and texts come with it, nothing needs installing, a phone with no eSIM slot works, and the charge lands on a bill you already pay. For a transit night, O2's £7 is the right call. One day on Three is about $11, close to the price of Ringo Light's whole 3-day trip.
Networks in Japan, and what changes for a visitor from the UK
Japan has three big networks, NTT Docomo, KDDI au and SoftBank, and all three cover the cities and the Shinkansen lines well. Docomo reaches furthest into the mountains and rural Hokkaido. Most travel eSIMs ride SoftBank or KDDI: Airalo names SoftBank, Holafly, Saily and Nomad name KDDI and SoftBank, and Ubigi names KDDI and NTT Docomo. Ringo Light uses a local partner network. For Tokyo, Kyoto, Osaka and Hiroshima I would not pick a plan on network.
The carrier passes have terms of their own. O2 calls the bolt-on unlimited, caps roaming speed at 2Mbps and names no fair use rule, and calls to the UK and within Japan are unlimited while other countries cost standard roaming rates. Receiving a call or text does not start the day charge, and you switch it on by texting TRAVEL to 23336. Three's daily charge unlocks UK calls, texts and up to 12GB of data for 24 hours, with the 12GB a monthly fair use limit and a surcharge beyond it. Hotspot use is not permitted, and partner networks may be slower. Three's page lists Japan under Rest of the World for Pay As You Go, outside Go Roam, so its daily charge is for Pay Monthly plans.
The travel eSIMs here are data only, with no Japanese number. Calls go over apps that use data, such as WhatsApp or FaceTime.
If you want a data bucket: Nomad or Ubigi
- Nomad, $16 for 10 GB. The cheapest 10 GB, and the cheapest 20 GB at $23, on KDDI au and SoftBank with 5G.
- Ubigi, $16.50 for 10 GB. On KDDI and Docomo, the widest coverage of the six.
- Saily, $17.99 for 10 GB. 20 GB at $24.99, with every Saily price taken from saily.com.
- Airalo, $18 for 10 GB. Its Moshi Moshi plan has 20 GB for $25, with buckets from $4 for 1 GB.
- ✓Ringo Light, no buckets. Its 2 weeks is unlimited for $21.99 and its 30 days unlimited for $54.99. For a fixed 10 GB, Nomad, Ubigi, Saily and Airalo are all cheaper in Japan, and their 20 GB buckets at $23 to $25 now cost more than the Ringo Light 2 weeks, though they last 30 days. I would buy Ringo Light for unlimited, not for a bucket.
What Ringo Light is
Ringo Light is Ringo's own data eSIM, and I write for Ringo, so weigh that. It is sold to fund the full Ringo, one plan that works everywhere with your own number ported onto it. For Japan it sells three trips, all unlimited data at full speed: 3 days at $9.99, 2 weeks at $21.99 and 30 days at $54.99. Nothing renews. The eSIM arrives by email in seconds and installs in one scan, no app.
It sits next to your own SIM, so your UK number keeps working for calls and texts if you leave roaming on for those. O2's page says calls to the UK and within Japan are unlimited and Three's daily charge includes UK calls and texts, though I would check how your carrier bills the day before leaning on that.
The card to buy it is further up this page, just after the side-by-side table.
Pick by trip
Ringo Light unlimited, 3 days, $9.99, against about $28 on O2 or about $23 on Three's 3-day pass. Nomad is $11.
O2 Travel. A single £7 day, no purchase and nothing to install.
Ringo Light unlimited, 2 weeks, $21.99, against about $131 on O2 or about $113 on Three's 14-day pass.
Ringo Light unlimited, 30 days, $54.99, against about $281 on O2 or about $322 on Three's daily charge. Ubigi at $65 for 60 GB on Docomo if you leave the cities.
Nomad 10 GB for 30 days at $16.
Keep your own SIM in beside the eSIM. O2 and Three carry calls and texts on your number and the travel eSIMs do not; the full Ringo, which Ringo Light funds, ports the number you have.
Frequently asked questions
How we compared, and our sources
Airalo, Holafly, Saily, Nomad, Ubigi, O2, Ringo Light, European Central Bank, Three, Ringo Light
We priced Airalo, Holafly, Saily, Nomad, Ubigi and Ringo Light for Japan on 10 November 2026, all on the same day, in US dollars. Each rival's price comes from its own website where it showed dollars, otherwise from an esimdb.com listing, and every source and its date is listed below. Ringo Light's prices come from the catalogue our checkout charges.
We compare the trips people actually book: a week, two weeks and a month of unlimited data, and a 10 GB bucket. We read each brand's fair use and speed rules and quote them as the brands state them. We did not run speed tests, so this page makes no speed claims for any brand.
Ringo Light is our own product. We put it in the table on the same terms as everyone else, and where a rival is the better buy the page says so.
Left out: Revolut. It sells Japan data plans of 1 GB for 7 days up to 20 GB for 30 days inside its banking app, for Revolut account holders only. Its website shows the plan sizes and a starting price in pounds, but no price per plan in dollars, and no unlimited plan, so it has no bar in the charts. Left out: Maya Mobile. I could not read its own prices for this country on the day, so it stays out rather than being guessed.
- Airalo: www.airalo.com/japan-esim?currency=USD, unlimited in dollars on the site, read 10 November 2026; buckets from esimdb.com/japan/airalo, listing dated 4 October 2026, not readable on 10 November 2026, figures kept from 25 October
- Holafly: esim.holafly.com/esim-japan/, prices in dollars on the site, read 10 November 2026
- Saily: saily.com/esim-japan/, prices in dollars on the site, 25 October 2026; not readable on 10 November 2026, figures kept from 25 October
- Nomad: www.nomadesim.com/japan-esim, prices in dollars on the site, read 10 November 2026; 10 GB and 20 GB on sale at $16 and $23; unlimited now sold for 3, 5, 7 and 10 days only
- Ubigi: cellulardata.ubigi.com/data-plans-and-coverage/ubigi-esim-data-plans/?destination=JPN, prices in dollars on the site, 25 October 2026; not readable on 10 November 2026, figures kept from 25 October
- O2: www.o2.co.uk/international/o2-travel, O2 Travel bolt-on page, read 31 October 2026: £7 a day, charged for the 24 hours from first use, unlimited data capped at 2Mbps while roaming, unlimited calls to the UK and within the destination; the destination is on the page's list of 75 countries. The roaming page at o2.co.uk/international/roaming returned not found on the same day
- Ringo Light: ringoesim.com/japan, the catalogue the checkout charges, read the same day
- European Central Bank: www.ecb.europa.eu/stats/eurofxref/eurofxref-daily.xml, euro reference rates of 30 October 2026, the latest published on 31 October 2026, used for the dollar figures (£1 = $1.34)
- Three: www.three.co.uk/go-roam, Go Roam daily charges, the 12GB fair use limit and passes at three.co.uk/go-roam, Japan in Around the World Extra at three.co.uk/support/roaming-and-calling-abroad/roaming-abroad/roaming-destinations, and the roaming FAQs, read 31 October 2026
- Ringo Light: our own catalogue, the prices the checkout charges on 10 November 2026.
Written and priced by the Ringo team. Prices change often; if you spot one that has moved, tell us through the contact page and we will update the table.
