Mobile data on a layover in Dubai, Doha, Istanbul or Singapore

Free Wi-Fi at the four big hubs

• Singapore (SIN): Changi says #WiFi@Changi is free in both the public and transit areas, with no account, email address or phone number. Select the network, open a browser and tap Connect Now.
• Istanbul (IST): the airport describes unlimited, free internet. On the iGA WiFi network you log in with a phone number and an SMS password, or with an access code from a terminal kiosk that scans your passport or ID. Turkish Airlines passengers use the TK WiFi network instead, with an SMS or their ticket number, seat number and surname.
• Dubai (DXB): when it launched its current service, Dubai Airports described free, unlimited high-speed Wi-Fi across its terminals, reached in one click from a landing page.
• Doha (DOH): Hamad International has a free Wi-Fi network in the passenger terminal. Check the connection steps on the airport's own site or the signs in the terminal, since they can change.

Two details matter more than speed. In Istanbul, the SMS password goes to whatever number you type, so your usual line has to be switched on to receive it; the passport kiosk is the way round that. And everywhere, Wi-Fi ends at the aircraft door, the bus to a remote stand or the security queue, which is exactly when a gate change or a rebooking message tends to arrive.

Why your EU plan is the expensive option here

The EU's Your Europe portal lists where roam like at home applies and says other countries are not covered by that regime. The UAE, Qatar, Turkey and Singapore are all outside it, so data on your usual line there follows your operator's international roaming prices, which Your Europe warns can be expensive. Its advice is to check with your provider before you travel, and Apple says the same in its roaming article.

The flight itself has its own trap. Your Europe notes that when a connection on a plane or ship is provided by satellite, EU rules no longer apply and there are no price caps; it suggests turning off roaming or using flight mode on board.

The safe setup is to turn off data roaming on your usual line before the first flight. On an iPhone with two lines it is per line: Settings, Cellular, the line, Cellular Data Options, Data Roaming. The reasons and the Android steps are in how to turn off roaming on your home line.

Is a short layover worth an eSIM?

For a connection of an hour or two spent between a gate and a café, often not. Free Wi-Fi covers messages, maps of the terminal and the airline's app, and you do not need more than that. Download your boarding passes before you leave home and keep them offline, in case the Wi-Fi login gets in the way at the wrong moment.

An eSIM for the hub country starts to pay off in other cases: a long overnight layover, a stopover of a day or two in the city, work on a laptop between flights, or a tight connection where you want data that does not drop between the gate, the bus and the plane. It also helps if the Wi-Fi asks for an SMS and your usual line is off.

Being careful costs very little with a Snoozim eSIM, because its validity starts when it first connects in its own country. If the layover is cancelled or you never switch the line on, the days have not started.

Two eSIMs: one for the hub, one for the destination

A phone can hold more than one eSIM, which is what makes this work. Apple says an iPhone can manage eight or more eSIMs, although it uses one cellular data line at a time. Google says a Pixel can store multiple eSIM profiles and use two at once on a Pixel 7 or later, with one SIM as the default for data.

So a trip from Madrid to Bali through Doha could carry three lines: your usual one for calls and texts, a Qatar eSIM for the layover and a destination eSIM for the rest. The same pattern works with a UAE eSIM in Dubai, a Turkey eSIM in Istanbul or a Singapore eSIM at Changi. A country eSIM only connects in its own country, so each one stays idle until you are there.

If you change planes at the same hub on the way back, the hub eSIM is still on the phone. If its data or its days have run out by then, a Snoozim top-up goes onto the same eSIM, with nothing to install again.

Install at home, switch on landing

Do the installation before the first flight, on home Wi-Fi. Apple says an iPhone needs Wi-Fi or a hotspot to activate an eSIM in most cases, and an airport login screen is a poor place to discover that. With Snoozim, the QR code reaches your email right after payment, with no app and no account, so it can be scanned at home. Give each line a clear label, such as Doha and Bali, so you know which is which later.

On landing at the hub, three changes: turn that eSIM's line on, choose it as the line for cellular data, and make sure data roaming is on for that line. On an iPhone the data line is chosen in Settings, Cellular, Cellular Data; on a Pixel, in Settings, Network and internet, SIMs, under Your primary SIMs. With iOS 26, Apple says the iPhone may also offer a Turn On Travel eSIM notification when you arrive.

At the final destination, repeat the move with the other eSIM and turn the hub line off, in Settings, Cellular on iPhone or with Use this SIM on a Pixel. If nothing loads, the order of checks is in do you need data roaming on for a travel eSIM and how to know if your eSIM is working.

Your number, a laptop, and what this guide leaves out

A Snoozim eSIM is data only, with no phone number of its own. Your usual line can stay switched on for calls and SMS, such as bank codes or the Istanbul Wi-Fi password, while its data roaming stays off. Apple also mentions a setting that lets the phone switch data lines in some situations; it is explained in allow cellular data switching.

If you want to work on a laptop during a long layover, hotspot is allowed on Snoozim eSIMs, so the phone can share its hub data with the computer instead of both fighting for the terminal Wi-Fi.

Leaving the airport during a layover is a separate question: whether you need a visa depends on your passport and the country, so check it with your airline and that country's official sources before you plan a trip into the city.