eSIM for Japan and South Korea: Price, Speed, Coverage
Going to both Japan and South Korea? Tokyo or Seoul — which has the better mobile internet? Compared: Docomo vs SK Telecom 5G speed, price, coverage.
Reviewed by ALT eSIM Editorial Team · Last updated 2026-05-21
Are they the same? Answer: no
Korea has the world's highest 5G penetration (SK Telecom + KT + LG U+). Seoul typical 80-200 Mbps; 5G coverage 30% denser than Japan. Docomo 5G is great in Tokyo / Osaka / Kyoto but rural areas fall back to 4G. Price-wise: similar (US$3-4/day unlimited both).
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