Train Wi-Fi on a Mac: make it usable, or switch to your hotspot

Train Wi-Fi usually reaches the internet over mobile networks along the track. All the passengers share that connection, so it is often slow.

Applies to: All current macOS versions. Instant Hotspot needs an iPhone or a cellular iPad with the same Apple Account as the Mac.Checked: 29 October 2026

Symptoms

The Mac joins and signs in, but pages load slowly or not at all.
Calls freeze and uploads stop.
The connection drops in tunnels and between stations, then comes back.
The sign-in page appears again after some time.

Likely causes

A shared connection. The train's connection serves all its passengers. A full train leaves little speed for each device.
Gaps in mobile coverage. Tunnels, cuttings and rural areas interrupt the mobile networks that the train uses.
Limits from the operator. Some operators limit the speed, the data or the time for each device. Some block streaming.
The sign-in, a VPN or custom DNS. Train Wi-Fi often has a sign-in page. A VPN or custom DNS can hide it, as on other public networks.
Background data on the Mac. Sync, backups and updates use the same small connection as your work.

How to check

In a browser, open http://captive.apple.com. If the operator's page opens, sign in.
Run Apple's speed test. Write down the result.
```
networkQuality
```
See which processes use the network now. Press q to stop.
```
nettop -P -d
```
Look at the mobile signal on your phone. Strong signal and few passengers can make the hotspot faster.

How to fix it

Turn on Low Data Mode for the train network. Choose Apple menu > System Settings > Wi-Fi.
Click Details next to the train network. Turn on Low data mode. Click OK.
Pause sync, backups and updates until you are on a better network.
In calls, turn off your camera. Audio uses much less of the connection.
If the train Wi-Fi is too slow, click the Wi-Fi icon. Choose your iPhone under Personal Hotspot.
Run the same speed test on the hotspot. Keep the faster of the two.
To stop the Mac from going back to the train Wi-Fi, open its Details. Turn off Automatically join this network.
On the hotspot, pause the apps that use data in the background. See Mac uses Personal Hotspot data in the background.
In tunnels and remote areas, the hotspot can drop too. Save your work before them.

With Kilobat

Find which part is slow: Wi-Fi, the router, the internet, DNS or the sign-in page.
```
kilobat diagnose
```
Check the sign-in page, and whether the network logged you out after an earlier sign-in.
```
kilobat portal
```
Test the speed with a limit on the data that the test uses.
```
kilobat speedtest --budget-mb 10
```
See live upload and download for each app. Press q to stop.
```
kilobat status --watch
```
Mark the train network as metered. Kilobat then treats it like a hotspot.
```
kilobat networks cost metered
```
For travel data packs, see Working from anywhere with a Mac: eSIMs, phone hotspots and making data last.

Questions

Is train Wi-Fi or my hotspot faster?

It depends on the route, the time and your carrier. Test both with the same test, then keep the faster one.

Does train Wi-Fi use my phone's data?

No. Train Wi-Fi does not use your data plan. The Personal Hotspot does.

Is train Wi-Fi safe for work?

Pages with https hide their contents from the network. Turn on a VPN after you sign in, if your work needs one.

Sources

Apple Developer News: How to modernize your captive network (22 June 2020)
Apple Support: Wi-Fi settings on Mac
Apple Support: Connect to the Personal Hotspot of an iPhone or iPad
Apple Support: Use Instant Hotspot to connect to your Personal Hotspot
Apple Developer: NWPath isExpensive
networkQuality(8) and nettop(1), man page installed with macOS 27.2

Checked on 29 October 2026.