Japan’s Mobile Market: 5G Expansion, Speed Rankings, and Regional Challenges

Japan’s Competitive Mobile Market and 5G Expansion

Japan’s mobile market continues to showcase innovation and intense competition among the four national operators: SoftBank, KDDI’s au, NTT DOCOMO, and Rakuten Mobile. The latest data from Ookla underlines how these companies are navigating the evolving 5G landscape, focusing on speed, coverage, and service quality in a saturated market. By early 2025, Japan reported 194 million cellular connections, reflecting a penetration rate of 157%, with operators now shifting their strategies toward improving 5G infrastructure and differentiating through network performance.

Performance metrics from Speedtest Intelligence reveal that SoftBank leads in median download speeds across all connection types at 62.05 Mbps, followed by KDDI’s au with 57.85 Mbps, Rakuten Mobile at 53.54 Mbps, and NTT DOCOMO at 50.50 Mbps. Interestingly, Rakuten Mobile delivers the fastest 5G median download speed of 128.39 Mbps, narrowly surpassing SoftBank at 127.45 Mbps, showcasing the aggressive efforts being deployed in the 5G race. However, these speeds do not fully reflect availability and end-user experience, especially for less connected regions in the country.

5G Coverage and Urban-Rural Divide

Despite achieving a reported 98.4% 5G population coverage by the end of fiscal year 2024, availability data highlights that access to 5G networks varies significantly. Availability measures how often users with 5G devices are connected to a 5G network, an area where NTT DOCOMO leads with a score of 38.4%, compared to SoftBank’s 26.5%, which is the lowest among major operators.

Japan’s concentrated urban population—over 92% of residents live in cities—makes urban areas hotspots for dense network investment. Prefectures such as Osaka and Tokyo post strong 5G availability and higher speeds, with Osaka achieving a median 5G download speed of 172 Mbps. However, rural prefectures like Yamanashi, with 5G availability at just 9.1%, expose the difficulties in extending network infrastructure to lower-density regions. Spectrum licences mandate providers to cover not only urban hubs but also rural and mountainous areas, presenting significant challenges to bridging this urban-rural divide.

Network Consistency and Regional Performance Disparities

The consistency of 5G speeds highlights further regional disparities. While urban areas such as Tokyo and Osaka enjoy reliable and high-speed 5G connections, rural regions often lag, both in availability and minimum speeds. SoftBank achieves standout consistency scores in areas like Hokkaido and Tōhoku, whereas some areas see significant variability, with minimum speeds as low as 4 Mbps in Nagano.

The relationship between availability and speed is also nuanced. Prefectures such as Osaka and Tokyo demonstrate higher availability correlating with stronger speeds. On the other hand, Yamagata achieves the fastest median 5G speed nationally—181 Mbps—despite lower availability, primarily due to reduced congestion in these less populous regions.

Future of Japan’s Telecom Networks

Japan’s 5G rollout has been shaped by robust regulation and sustained investment, ensuring nearly universal population coverage. However, the uneven distribution of availability and speed underscores a critical challenge: enabling consistent quality of service across all regions. For operators, focusing on targeted investments in underconnected areas will be crucial to closing the urban-rural connectivity gap. Without these efforts, disparities in network experience are likely to persist.

As Japan continues to innovate in mobile connectivity, global audiences can look forward to how developments in 5G will contribute to industries like IoT, edge computing, and beyond. Events such as the IoT Tech Expo highlight the transformative role of advanced networks in shaping the future of connectivity and digital services.