Field data · Japan

Mobile data speed in Japan: our field tests

Direct answer

Our eSIM Japan field tests include 12 measurements taken across 12 locations. The most recent measurement was taken on June 30, 2026. Median download speed is 79.9 Mbps and median latency is 182.5 ms. These results describe only the tested locations and not nationwide coverage.

Real mobile speed measurements taken on the ground in Japan, with our own eSIM. 12 test(s) so far.

12 measurements

79.9

Median speed (Mbps)

Tokyo Haneda Airport Hnd

Fastest place

182.5

Median latency (ms)

Measurements

Map of measurements

By operator

Measurement detail

By city: Download (Mbps)

	Median	Mean	Min	Max	Tests
Nagoya	135.0	135.0	135.0	135.0	1
Sapporo	103.8	103.8	18.6	189.0	2
Tokyo	88.5	103.8	40.9	221.0	7
Shizuoka	27.5	27.5	27.5	27.5	1
Osaka	19.3	19.3	19.3	19.3	1

By city: Upload (Mbps)

	Median	Mean	Min	Max	Tests
Tokyo	17.0	18.8	9.4	29.3	7
Sapporo	14.8	14.8	3.8	25.9	2
Osaka	12.6	12.6	12.6	12.6	1
Nagoya	3.8	3.8	3.8	3.8	1
Shizuoka	3.6	3.6	3.6	3.6	1

By city: Latency (ms)

	Median	Mean	Min	Max	Tests
Tokyo	182.5	178.5	161	188	4

By operator: Download (Mbps)

	Median	Mean	Min	Max	Tests
NTT Docomo	79.9	93.0	18.6	221.0	12

By operator: Upload (Mbps)

	Median	Mean	Min	Max	Tests
NTT Docomo	13.8	15.1	3.6	29.3	12

By operator: Latency (ms)

	Median	Mean	Min	Max	Tests
NTT Docomo	182.5	178.5	161	188	4

How we measure

Every measurement is taken on location, with our own eSIM, in real travel conditions: a precise place, a time, a connected network. We record download and upload speed, latency, then publish the result unedited.

The aggregates (median, mean, extremes) build up as we travel. The more measurements a destination has, the more reliable its median becomes. The median resists the extreme values of a single test better than the mean.