The home line goes down, you are working on a train or in a holiday rental with no Wi-Fi: the smartphone becomes the laptop's modem. Every modern phone has this feature, but using it well takes a little care. Otherwise you may end up with a flat battery, a scorching phone and your data allowance gone by midday.
Three ways to share the connection
| Method | Speed | Battery drain | When to use it |
|---|---|---|---|
| Wi-Fi hotspot | high | high | several devices, flexible use |
| USB tethering | highest and most stable | the phone charges | one computer, long sessions |
| Bluetooth tethering | low | low | email and messages, emergencies |
Wi-Fi hotspot
The phone creates a small Wi-Fi network that computers, tablets or other devices can join. It is the most convenient method, but it keeps two radios on at once, cellular and Wi-Fi, so it is the most power-hungry.
USB tethering
You connect the phone to the computer with a cable and turn on USB sharing. The connection is more stable, unaffected by radio interference, and the phone charges in the meantime. For a day's work on a laptop it is the best solution. You need a cable that carries data, not just power: a detail that wastes time more often than you would think.
Bluetooth tethering
Limited speed but low power use. Handy for reading email on a tablet or sending a document when the battery is low, not for video calls.
Setting up the hotspot properly
A few settings deserve attention:
- name and password: change the default name, which often contains the phone model or the owner's name, and use a long password;
- WPA3 protection or, if some device does not support it, mixed WPA2/WPA3 mode;
- band: 5 GHz offers more speed and less interference; 2.4 GHz is for older or more distant devices;
- automatic shut-off when no device is connected, so as not to waste battery;
- maximise compatibility: on some phones an option improves compatibility with older devices at the expense of speed; turn it on only if needed.
The real problem: data usage
A computer connected to a hotspot behaves as if it were on an unlimited connection: it updates the system, syncs the cloud, downloads app updates and plays high-definition video. In a short time it can use as much data as the smartphone alone would use in weeks.
To avoid this, tell the computer it is on a metered connection:
- on Windows, turn on "Metered connection" in the Wi-Fi network properties: updates and some syncing are paused;
- on macOS, phone hotspots are often recognised automatically and some background activity is reduced; it is still wise to pause heavier cloud syncs;
- in sync apps such as cloud services and backup clients, many let you pause uploads on metered networks.
Other practical steps: lower video call quality, close browser tabs with autoplaying video and postpone large downloads.
Plan limits
Some mobile plans, especially those with very large or unlimited data, have specific conditions for connection sharing: a dedicated cap, reduced speed or extra charges. It is worth checking your plan's terms before relying on the hotspot for work, rather than finding out at the end of the month.
Battery and heat
A hotspot running for hours heats the phone, especially when the signal is weak and the radio has to work harder. For long sessions:
- keep the phone somewhere ventilated, not under the laptop or in the sun;
- prefer USB tethering, which charges while sharing;
- place it where the cellular signal is best, for example near a window: a good signal reduces both power use and heat.
In short
- The Wi-Fi hotspot is the most convenient, USB tethering the most stable and easiest on the battery.
- A strong password, WPA3 and automatic shut-off make the hotspot safer and more efficient.
- Setting the connection as metered on the computer avoids exhausting your data.
- Many plans have specific rules for sharing: check them beforehand.
- For long sessions, aim for ventilation, a good signal and a phone on the cable.
