Fastest 4G SIM cards for short-term stays in Japan?

I have just spent a few weeks in Japan. During that time my wife and I used two different short-term SIM cards and one pocket Wi-Fi, but we were surprised by how slow the Japanese 4G networks were compared to Europe. Our SIM card used the IIJ, Softbank and NTT Docomo networks, but the speed was between 10 and 20 Mbps. We stayed in central Tokyo and travelled to many other cities, but it was the same everywhere. In Western Europe we are used to speeds of 40 to 150 Mbps.

I checked the average mobile network speed by country (Speedtest Global Index) and Japan only ranked 55th worldwide, which is not great (ranked between Suriname and Albania!), but they mention an average speed of 47 Mbps - still a far cry from what we experienced.

I was wondering if the speed was lower because we used 'tourist' SIM cards? Could Japan residents confirm what speed they usually get with a long-term subscription?

I have just checked the internet speed on my iPhone 13 (AU KDDI), running four tests:

• 58.7, 47.7, 64.7, 62.7 Mbps download
• 92.1, 90.0, 87.3, 93.1 Mbps upload

Latency 6ms. Quite fluctuating.

Scrap the data above. I forgot to disable WiFi. Without WiFi, things look bleak:

• 19.7, 20.2, 18.1, 18.2 Mbps download
• 2.63, 3.15, 2.83, 4.95 Mbps upload

thomas said:

Scrap the data above. I forgot to disable WiFi. Without WiFi, things look bleak:

• 19.7, 20.2, 18.1, 18.2 Mbps download
• 2.63, 3.15, 2.83, 4.95 Mbps upload

Click to expand...

So it seems to be similar with a subscription.

Wi-Fi is not so fast either. In Belgium we typically get 200 to 300 Mbps, but some people can get 1000 Mbps. In an Airbnb in Spain I had over 500 Mbps.

15 to 20 years ago Japan had faster Internet connections than most of Europe. Apparently it's no longer the case. I wonder what happened.

On my laptop, I get 649.9 Mbps download, and 539.1 Mbps upload. Not too shabby.

thomas said:

On my laptop, I get 649.9 Mbps download, and 539.1 Mbps upload. Not too shabby.

Click to expand...

Big difference with the results you got on your phone by Wi-Fi! Maybe you weren't near the box when you tested it?

For fixed broadband Japan does better than 4G in terms of international ranking. It's 16th with an average download speed of 188 Mbps.

[January, 2024] Plan popularity 10 line transmission rate ranking for exclusive use of the bargain SIM& online.

●Speed test Top 3 average downhill speeds (12 o'clock/around Tokyo Station)
1st Ymobile: 120.37Mbps
2nd LINEMO: 91.27Mbps
3rd povo: 74.57Mbps

●Top 3 app download speeds (12 o'clock/around Tokyo Station)
1st Ymobile: 61.79Mbps
2nd LINEMO: 46.11Mbps
3rd povo: 41.15Mbps

I used an Airalo eSim last week. I didn't have any issues and it was generally fast enough for me but I wasn't watching videos or anything like that. I ended up using only 2GB for the week because I was mostly in my office or hotel on wifi. But it worked well for me when I was out and about even within the subway.