Does Texting Use Data?

A standard SMS uses no mobile data whatsoever. It travels on the signalling channel the network uses to manage your phone, which is why a text can get through when data is unusable and why it is billed per message rather than per megabyte.

Messaging apps do use data, but so little that measuring it is a waste of attention. The number worth knowing is not how much texting costs — it is which kind of message costs you money while you are abroad.

Rough figures for a day of ordinary conversation:

• SMS: no data at all. Charged per message by your carrier, at international rates when roaming.
• Text over WhatsApp, Signal, iMessage or Messenger: a few kilobytes per message. A busy day of pure text is well under 5 MB.
• Photos: 100 KB to 3 MB each, depending on the app’s compression and whether it sends full resolution.
• Voice notes: roughly 250 KB per minute.
• Video clips: 5 MB to 50 MB, and the single item on this list that can matter.

So the honest summary is that texting is free in every practical sense and sending video is not. Nothing in between deserves thought.

Not data — SMS. A text sent from your home line while roaming is billed at your carrier’s international rate, and unlike data there is no travel plan that covers it, because a travel eSIM has no number of its own. The one broad exception is regional: the EU roaming regulation, in force to 2032 outlaws surcharges on texts sent on an EU plan while travelling in the EU and EEA. Everywhere else, the ways to avoid roaming charges are worth reading before you fly.

The inverse also holds and surprises people more: an app message costs a fraction of a penny of data whatever country you are in. Sending fifty WhatsApp messages from Tokyo costs less than sending one SMS.

The expensive case is not choosing SMS. It is an app quietly choosing it for you.

RCS narrows the trap without closing it. On iOS 18 and later a green message can go over RCS, which travels on data like any other app message, but Apple’s page on turning RCS messaging on is clear that it needs a carrier that supports RCS and that carrier fees can still apply. Where RCS is not available, the message drops to SMS and is billed as one.

Receiving an SMS is normally free, which matters more than it sounds: bank codes, airline updates and login verifications all arrive that way, and they arrive on your home number rather than on the travel plan.

Keeping the home line switched on with its data roaming off lets those through at no cost, and Wi-Fi Calling covers it where there is wifi and no cellular signal.

Not messaging. Maps, browsing, social feeds and video are where a travel allowance goes; text is a rounding error in every plan we list. The realistic estimate is worth a minute. Plans by destination, ranked on price per GB.