Using mobile data in Réunion: what to expect
Réunion is a French overseas department in the Indian Ocean, and that status shapes its mobile picture more than most travellers expect. The networks here are French-run and well built around the coastal ring where nearly everyone lives, with 4G across the populated belt and 5G expanding in and around Saint-Denis and Saint-Pierre. For the everyday rhythm of a Réunion trip — navigating the switchback mountain roads, looking up a hiking trailhead, translating a menu, calling a gîte owner, uploading photos from a volcano viewpoint — you'll have dependable data along the coast and on the main routes. There's a useful quirk too: because Réunion is an outermost region of the European Union, an EU-wide travel plan can cover it on the same eSIM as mainland Europe, which is genuinely handy if your trip begins in Paris. Whichever plan you pick, the eSIM activates on arrival and there's no roaming bill — the usual sting on a far-flung island carrier.
Coverage across Réunion
The island is essentially a coastal ring of towns wrapped around a wild, mountainous interior, and coverage follows that geography closely.
- Strong: the coastal corridor — Saint-Denis, Saint-Paul, Saint-Gilles-les-Bains, Saint-Pierre and Le Tampon — plus the ring road and the main routes linking them.
- Weak or absent: the interior cirques of Mafate, Cilaos and Salazie, the high trails around the Piton de la Fournaise volcano, and the forest roads climbing into the Hauts. Mafate in particular is reachable only on foot or by helicopter, and you should plan as if there's no signal there at all.
If you're hiking the cirques, walking the volcano rim or driving up to the Maïdo lookout, save your offline maps before you leave the coast — the terrain swallows signal quickly the moment you head inland or gain altitude.
How much data you'll need
Réunion is an active, outdoorsy destination, so data use leans heavily on Maps for those endless hairpin roads, plus WhatsApp, Instagram for the scenery, and translation if your French is rusty. A long weekend based on the coast is fine on roughly 3-5 GB; a week to ten days mixing beaches, the cirques and the volcano typically lands around 10-15 GB once you factor in all the navigation and photo uploads; heavy streaming or tethering a laptop for work is calmer on an unlimited-style plan. Two things push usage higher than a typical island trip here: the constant map use on roads that fold back on themselves dozens of times, and the temptation to share the scenery in real time. The plans above list what's live — pick mid-range if you're unsure, and topping up later is quick and doesn't drop your connection or change your number.
Keep your number and WhatsApp
There's no need to drop your home number for a Réunion data line. A dual-SIM phone runs the eSIM beside your normal SIM: the eSIM carries the data while your usual number keeps taking calls, SMS and banking codes, and WhatsApp stays on your existing number with nothing to re-register. Just switch your home SIM's data roaming off so it can't quietly charge you in the background while the eSIM handles everything. This matters even on an EU territory like Réunion: if your home carrier is from outside Europe, the roaming rules you're used to may not apply the way you assume, so it's safest to let the eSIM carry all the data and keep the home line for voice and texts only.
Before you fly
Confirm your phone supports eSIM — most iPhones from the XR on, plus recent Samsung, Pixel and Honor models; our compatibility checker tells you in seconds. Install over home Wi-Fi a day or two ahead; the plan stays dormant and starts only when you first connect on the island. It activates on arrival at Roland Garros (RUN) near Saint-Denis, or at Pierrefonds (ZSE) outside Saint-Pierre if you're flying in from elsewhere in the region.
Combining Réunion with mainland Europe?
Because Réunion sits inside the EU, an EU regional plan can keep you connected across mainland Europe and the island on one eSIM — ideal if you're routing through France before flying down. For a Réunion-only trip, a country plan is the simplest and cheapest way to land online, and you can re-run the device checker if you upgrade your phone before departure.