SoftBank Speed Test - Japan | Kencang
Test your SoftBank internet speed in Japan
www.softbank.jpSoftBank is Japan's third-largest mobile carrier with over 56 million subscribers. The company operates a nationwide 5G and 4G LTE network and leads Japan in 5G time availability. SoftBank also offers fiber broadband through SoftBank Hikari and wireless home internet through SoftBank Air.
About SoftBank
SoftBank Corp. traces its telecommunications roots to 2006 when SoftBank Group acquired Vodafone Japan. Masayoshi Son founded SoftBank Group in 1981 as a software distributor, and the Vodafone acquisition marked its entry into the mobile carrier business. The company rebranded Vodafone Japan to SoftBank Mobile and rapidly expanded.
SoftBank Corp. is headquartered in Minato, Tokyo, and operates as a subsidiary of SoftBank Group Corp. The carrier also runs Y!mobile as a mid-tier brand and LINEMO as an online-only budget brand. Together, these three brands cover premium, mid-range, and budget segments of the Japanese market.
SoftBank launched commercial 5G in March 2020 and has since expanded its 5G coverage across all major urban areas. Recent reports show SoftBank leading in 5G time availability, meaning users spend more time connected to 5G signals compared to other carriers.
SoftBank Plans and Services
SoftBank offers several internet plans across different technologies and price points.
SoftBank's primary unlimited plan is Merihari Unlimited+ at JPY 7,425 per month. Users who consume less than 2 GB in a billing cycle pay only JPY 5,775. The plan includes 5G access and various family discounts.
For budget users, LINEMO starts at JPY 990 per month for 3 GB with LINE app data not counting toward the cap. Y!mobile offers mid-tier plans from JPY 2,365 with in-store support and family discounts. All three brands use the same SoftBank network.
SoftBank Hikari provides 1 Gbps fiber broadband using the NTT FLET'S network at JPY 5,720 per month for houses. A 10 Gbps plan is available in select areas. SoftBank Air offers wireless home internet at JPY 5,368 per month with 5G speeds and no installation required. Both products include mobile bundle discounts of JPY 550-1,100 per line.
SoftBank Internet Plans
| Plan | Speed | Price | Features |
|---|---|---|---|
| Merihari Unlimited+ mobile | 5G/4G LTE | JPY 7,425/month |
|
| LINEMO Best Plan mobile | 5G/4G LTE | JPY 990/month |
|
| SoftBank Hikari (House) fiber | 1 Gbps | JPY 5,720/month |
|
| SoftBank Air 5G fixed-wireless | 2.1 Gbps | JPY 5,368/month |
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Prices and availability may vary by location. Contact SoftBank for current offers.
SoftBank Coverage by Region
SoftBank performance varies by location. Coverage density, local infrastructure, and network congestion affect speeds in each market.
Tokyo Metropolitan Area
Highest 5G availability time in Tokyo among all carriers
Osaka-Kyoto-Kobe (Kansai)
SoftBank Hikari available since it uses NTT FLET'S network
Rural and Regional Areas
SoftBank Air is an option where fiber installation is difficult
Is SoftBank Right for You?
Every provider has trade-offs. Here is how SoftBank performs based on real-world usage and customer feedback.
Strengths
- Highest 5G time availability among Japanese carriers
- LINEMO at JPY 990 is one of Japan's cheapest plans with carrier-grade 5G
- Three brands (SoftBank, Y!mobile, LINEMO) covering all price segments
- SoftBank Air wireless home internet needs no wiring or installation
- PayPay integration for cashback and rewards on purchases
- SoftBank Hikari bundle discount saves JPY 550-1,100 per mobile line
- Y!mobile offers in-store support at budget prices
Weaknesses
- Merihari Unlimited+ at JPY 7,425 is the most expensive among the big three
- SoftBank Hikari uses NTT FLET'S network, not an independent fiber like au Hikari
- SoftBank Air speeds can be inconsistent. Depends on local 5G/4G conditions
- Fewer 5G base stations than DoCoMo in some suburban areas
- LINEMO is online-only with no in-store support
Best For
- Budget users who want LINEMO at JPY 990 per month for 3 GB
- Users who want the highest 5G time availability
- PayPay users who benefit from SoftBank cashback campaigns
- Users who need wireless home internet (SoftBank Air) without installation
- Families using Y!mobile with in-store support and family discounts
Not Ideal For
- Users who want the cheapest unlimited data (Rakuten Mobile is cheaper)
- Those who prefer an independent fiber network (au Hikari is separate from NTT)
- Rural users where SoftBank 5G coverage is limited
- Users who need consistent home internet speeds (fiber is more reliable than SoftBank Air)
How SoftBank Compares
Side-by-side comparison of SoftBank against major competitors in Japan.
| Competitor | Speed | Price | Coverage | Verdict |
|---|---|---|---|---|
| Ntt Docomo | SoftBank leads in 5G time availability. DoCoMo has more 5G base station locations. Peak speeds are comparable. | SoftBank LINEMO at JPY 990 for 3 GB. DoCoMo ahamo at JPY 2,970 for 20 GB. LINEMO is cheaper for light users. | Both cover all of Japan with 4G. SoftBank users report more time on 5G. DoCoMo has wider geographic 5G reach. | Choose SoftBank for LINEMO value and PayPay rewards. Choose DoCoMo for widest 5G coverage and d-point ecosystem. |
| Au Kddi | Similar 5G and 4G speeds in most areas. au offers 10 Gbps fiber. SoftBank offers wireless home internet alternative. | SoftBank LINEMO at JPY 990. au UQ Mobile at JPY 2,365. SoftBank has cheaper entry point. | Comparable nationwide 4G and 5G coverage. au has satellite connectivity via Starlink Direct. | Choose SoftBank for cheapest entry (LINEMO) and SoftBank Air wireless option. Choose au for independent fiber and satellite. |
Troubleshooting SoftBank Issues
Common SoftBank connection problems and how to fix them.
SoftBank Air wireless home internet is much slower than expected
Cause: SoftBank Air depends on local 5G/4G signal strength. Walls, building materials, and distance from tower all affect speed.
- Place the SoftBank Air unit near a window facing the nearest cell tower
- Avoid placing the unit on the floor or behind furniture
- Check if your area has 5G SoftBank Air coverage on the SoftBank website
- Test at different times. Peak evening hours (7pm-11pm) will be slower
- Contact SoftBank to check if a firmware update is available for your unit
SoftBank mobile speeds are below expected 5G performance
Cause: Device connected to 4G instead of 5G, or in a congested area during peak hours.
- Check your phone settings to confirm 5G mode is enabled
- Move to an outdoor location with better signal
- Toggle airplane mode to reconnect to a different tower
- Restart the device to refresh network connections
SoftBank History
Key milestones in SoftBank development and network expansion.
SoftBank Group acquired Vodafone Japan for JPY 1.75 trillion and launched SoftBank Mobile
Became first Japanese carrier to sell iPhone, starting exclusive Apple partnership
Launched SoftBank Hikari fiber broadband and SoftBank Air wireless home internet
Launched Y!mobile brand for mid-tier customers with physical store support
Launched commercial 5G service in March alongside DoCoMo and au
Launched LINEMO online-only brand starting at JPY 990 per month
Achieved highest 5G availability time among Japanese carriers in Opensignal reports
Test Your SoftBank Speed
Run a free speed test to check if SoftBank delivers the speeds you are paying for. Test during peak evening hours for the most realistic results. Compare your results against SoftBank advertised speeds above.
SoftBank Speed Test FAQ
How fast is SoftBank 5G in Japan?
SoftBank 5G delivers download speeds of 400 to 1,500 Mbps in areas with Sub-6 coverage. In Tokyo and Osaka city centers, typical 5G speeds range from 300 to 800 Mbps. SoftBank leads Japanese carriers in 5G availability time, meaning users spend more connected minutes on 5G compared to DoCoMo and au. The theoretical maximum speed is up to 3.4 Gbps on Sub-6 bands. 4G LTE averages 50-180 Mbps depending on location.
What is the cheapest SoftBank plan available?
LINEMO Best Plan starts at JPY 990 per month for 3 GB of data on the SoftBank 5G and 4G network. LINEMO includes free data usage for the LINE messaging app, so LINE chats, calls, and video calls do not count toward the 3 GB cap. LINEMO is managed entirely online with no physical store support. For users wanting in-store support, Y!mobile starts at JPY 2,365 per month for 4 GB with access to Y!mobile retail stores across Japan.
Is SoftBank Air a good alternative to fiber?
SoftBank Air provides wireless home internet using 5G and 4G signals at JPY 5,368 per month with unlimited data. It requires no installation or wiring. In areas with strong 5G coverage, speeds can reach 200-500 Mbps. The main advantage is convenience, since it works by plugging into a power outlet. The drawback is speed variability. SoftBank Air depends on local signal conditions, so speeds during peak evening hours may drop below 50 Mbps. Fiber is more consistent for heavy users, gamers, and remote workers.