Indonesia is seventeen thousand islands with wildly different connectivity, and most visitors experience a small and well-covered slice of it. Bali and Java are straightforward. The moment you head for Komodo, Raja Ampat or a volcano at four in the morning, the picture changes completely.
Nyepi: the day Bali switches off
This is the single most important thing on this page if your dates fall near it. Nyepi, the Balinese Day of Silence, shuts the entire island down for twenty-four hours. The airport closes. Nobody goes outside, including tourists, who are expected to remain within their accommodation. Lights are kept low and noise to a minimum.
Crucially, mobile internet is typically switched off across Bali for the day. Not slow — off. Fibre-based hotel Wi-Fi generally keeps running, so accommodation on a wired connection may still work — but cellular is the part that goes dark, and that is what your eSIM uses.
If your trip overlaps with Nyepi, plan for it properly: no flights in or out that day, no leaving your hotel, and no data. Download everything beforehand, tell family at home in advance so nobody worries, and treat it as what it is — a genuinely extraordinary thing to witness, not an inconvenience. The date moves each year with the Balinese calendar, so check it against your dates before you book.
Bali traffic and why apps matter
Bali's roads have not kept pace with its visitors, and journeys take far longer than the distances suggest. Canggu to Uluwatu can be two hours. Ubud to the south coast is a serious undertaking in the afternoon.
Gojek and Grab both operate and both book motorbike taxis as well as cars, which in Bali traffic is transformative — a bike gets through what a car sits in. They fix the fare, which removes the negotiation, and they need data to work.
One honest caveat: in some areas local transport cooperatives restrict app pickups, and you will see signs saying so. In those spots you use a local driver instead. It is not a problem, but it is worth knowing rather than being confused by it.
What coverage is honestly like
Bali's south and centre — Kuta, Seminyak, Canggu, Ubud, Sanur, Uluwatu — have solid 4G with 5G in places. Jakarta, Yogyakarta, Surabaya and the main Javanese cities are well covered, as are Lombok's west coast and the developed parts of Nusa Penida.
It falls away quickly beyond that. The Gili Islands have limited coverage. Komodo and Flores boat trips lose signal offshore for long stretches. Raja Ampat is genuinely remote. The pre-dawn climbs up Bromo and Ijen, and much of interior Sumatra and Sulawesi, have little or nothing.
Download offline maps for every island you visit, and treat boat days as offline.
The networks you will connect to
Telkomsel has by far the widest national reach and is usually what still works on smaller islands. Indosat Ooredoo Hutchison, XL Axiata and Smartfren are the other major operators, strongest in the cities. A travel eSIM roams onto whichever partner network is strongest where you are, which across an archipelago this size matters more than usual.
Fast boats and sea conditions
Crossings to the Gilis, Nusa Penida and Lombok are made by fast boat, and they are cancelled or delayed for sea conditions with limited notice. Operators announce on their own channels first.
Confirm your crossing the night before and again in the morning, screenshot your ticket, and send any time-sensitive message before you board. The middle of a crossing has no signal, and the boats are loud enough that you would not hear a call anyway.
Scooters, and navigating on one
Renting a scooter is how a great many visitors get around Bali and Lombok, and navigation becomes the thing you rely on most. Mount the phone rather than holding it, download the island map offline, and be aware that the small roads change surface and width without warning.
Check your travel insurance and licensing position before you ride. It is a common and expensive gap.
Temples, dress and the small rules
Balinese temples require a sarong and sash, sometimes provided and sometimes not, and there are additional restrictions that vary by temple. Some sites limit entry at certain times for ceremonies, which are frequent and not always announced far ahead.
Checking the specific temple before a long drive saves the drive. Ceremonies also close roads without warning, which is its own reason to have live navigation.
How much data you will actually use
Plan on 5 to 7 GB for a week. Ride apps, navigation, translation and heavy photo sharing add up, and Indonesian trips tend to run long — two or three weeks is common.
At that length unlimited usually makes more sense than counting. Turn off automatic cloud photo backup over cellular before you fly.
Timing your plan to the trip
Indonesian itineraries stretch. People add Nusa Penida, stay another week in Ubud, take the boat to Flores after all. Choose a plan with room in it rather than one expiring exactly when the original plan said.
Install at home on Wi-Fi before you fly. The profile stays dormant until it first connects to an Indonesian network, so a long flight with a stopover does not consume it.
Who this suits
Anyone in Bali using Gojek or Grab, which should be everyone. Scooter riders who need offline maps. Island hoppers taking fast boats. Volcano climbers heading out before dawn. Long-stay visitors and remote workers in Canggu or Ubud. And anyone whose dates fall anywhere near Nyepi.
Nusa Penida and the day-trip crush
Nusa Penida has become the standard Bali day trip, and the standard version of it involves a fast boat, a scramble for a driver at the port, and several hours on roads that are steep, narrow and busier than the island can comfortably carry. The famous viewpoints have queues.
Booking a driver in advance rather than negotiating at the pier makes the day dramatically better, and it is arranged by message. Going early, or staying a night, avoids the crush entirely.
Coverage is reasonable near the ports and thin on the cliff roads and at the far viewpoints, so download the island map before you board.
Before you book
A data plan is the easy part. The part worth doing first for Indonesia is the paperwork: check the current entry requirements · how the checker works · browse the region.
Frequently asked questions
What happens to my data during Nyepi?
Mobile internet is typically switched off across Bali for the twenty-four hours of Nyepi, and the airport closes. Download what you need in advance and tell family at home so nobody worries. The date moves each year, so check it against your travel dates.
Do Gojek and Grab work in Bali?
Yes, and they book motorbike taxis as well as cars, which is far faster in Bali traffic. Note that some areas restrict app pickups in favour of local drivers, and you will see signs where that applies.
Will I have signal on the Gili Islands or a Komodo boat trip?
Limited on the Gilis and largely none offshore on Komodo and Flores trips. Confirm your crossings in advance, screenshot tickets and treat boat days as offline.
How much data do I need for two weeks in Indonesia?
Plan on 10 GB or more, or go unlimited. Ride apps, scooter navigation and photo sharing all add up, and trips here usually run longer than a standard holiday.