Why is my internet so slow abroad?

Slow data abroad is usually the network you are borrowing, not the eSIM you bought. A travel eSIM is a guest on someone else's towers, and a guest gets what the host gives. That said, four of the six things that slow you down are things you can act on in a minute. Here is the honest list, from the causes you cannot change to the ones you can.

Nobody can promise you a speed abroad, and anyone who does is guessing.

You are a guest, and guests are served second

Your plan connects you to a local operator through a roaming agreement. Their own customers and your traffic are not necessarily treated the same when the network is busy: operators can and do give roaming traffic a lower priority than the subscribers who pay them every month. At three in the morning you will never notice. At six in the evening in a city centre, you will.

Nothing in the phone changes this. It is the price of not buying a local SIM, and on most trips it is a fair trade.

Day passes run at full speed, then keep going slower

A day pass gives an allowance each day at full speed, and once that allowance is used the connection does not stop: it continues at a reduced speed until the allowance resets the next day. That is the design, not a fault.

The reduced speed is comfortable for messages, maps and mail, and uncomfortable for video calls and streaming. So a day that suddenly turns slow in the evening is usually not the network at all. Check the app first.

The cell above your head is full

Mobile capacity is shared per cell, so a stadium, a festival, an airport gate area or a station at rush hour can crawl while a street two hundred metres away is fine. This affects locals and visitors alike, and is why speed tests taken at an airport tell you almost nothing about a country.

Walking out of the crowd is a genuine fix. So is waiting twenty minutes.

3G has been switched off in a lot of places

If your mental model is "when 4G is weak the phone falls back to 3G", that model is out of date. The GSA counted 303 completed, planned or in progress 2G and 3G switch offs across 88 countries and territories by December 2025, with 167 operators in 67 markets working on 3G specifically and 80 of them already finished.

Where 3G is gone, there is no soft middle gear any more. Either the phone holds 4G or 5G, or it has almost nothing. It also means an old device that only speaks 3G will not work at all in those countries, no matter which eSIM is in it.

Your phone picked a band that reaches far but carries little

Low frequency bands travel through walls and across valleys; high frequency bands carry much more data over a short distance. The phone chooses on signal strength, so indoors it will often sit happily on the band that reaches you rather than the band that would be faster if you stepped towards a window.

This is why moving a few metres, or going outside, sometimes changes everything. It is also why a "5G" icon is not a promise: most 5G you meet abroad is the non standalone kind, resting on the 4G core beneath it.

Where your data leaves the network

On some plans your traffic does not reach the internet in the country you are standing in. It travels to a gateway elsewhere first. Our China plans exit through Hong Kong, which is exactly why Google, WhatsApp and Instagram open there without a VPN. Our UAE plan exits through Europe, which is the reason WhatsApp and FaceTime calls usually work in the Gulf on it.

That routing costs something, and the cost is latency. Every packet makes a longer trip, so pages feel a beat slower to start and video calls have a little more lag, even when the throughput is perfectly good. It is a deliberate trade: a slightly longer round trip in exchange for an open internet.

What to actually try

1. Check the app. Full speed allowance used, or plan finished, explains more slow days than anything technical.
2. Airplane mode on for fifteen seconds, then off. It makes the phone re register and often lands it on a better cell.
3. Move. Outdoors, away from the crowd, towards a window. Bands change with a few steps.
4. Try 4G instead of 5G. On iPhone: Settings, Mobile Data, Mobile Data Options, Voice & Data, LTE. On Samsung: Settings, Connections, Mobile networks, Network mode. A stable 4G connection beats a 5G one the phone keeps losing.
5. Pick the operator by hand. Network Selection on iPhone, Network operators on Samsung. The plan page says which operators your plan uses.
6. Test at a sensible moment. A speed test in an airport queue is a measure of the queue.

If it stays slow in a quiet place, at a quiet hour, with allowance left, then something is genuinely wrong and we want to hear about it. Write to support with the country, the operator name your phone is showing, and roughly when. That is enough for us to check the route.

Quick answers

Is a travel eSIM slower than a local SIM?

Often slightly, yes, for the reason at the top: roaming traffic can be given lower priority when a cell is busy. In normal conditions the difference is not something you feel, and it buys you a line that works the minute you land.

Does the plan slow down on purpose when I have used a lot?

On a day pass, yes, and that is stated up front: a full speed allowance each day, then a reduced speed until the next day. On the other plans there is no shaping. They simply have an amount of data in them.

Why does a video call lag when downloads seem fine?

Because calls care about latency and jitter, not throughput. A long route to the gateway, or a busy cell, hurts a live call long before it hurts a download. Turning the camera off helps more than anything else.