The short answer
Nearly every long-haul route to Bali connects somewhere, most often Singapore, Kuala Lumpur or Bangkok, and for most travellers the right move is to keep that connection short and stay airside. A few hours in a transit terminal is not a wasted day: it is the calmest and cheapest way to break a very long journey. Going into the city only pays off when you have real time, which in practice means most of a day, or a night you booked on purpose. The rest of this page is about telling those two situations apart, and about the one piece of admin worth doing in advance either way.
Layover or stopover: the difference that matters
A layover is a connection you pass through on the way to somewhere else; a stopover is a deliberate stay of a night or more, built into the ticket. The distinction changes what you have to do. On a short connection with both flights on one booking, your bags are usually checked through and you may never leave the transit area. Add a night and you clear immigration, collect your luggage, and need a bed plus a way back to the terminal. Some airlines let you build a stopover into a Bali fare for little or no extra fare, which is worth checking before you book two separate tickets.
How long a layover has to be before leaving the airport
As a rough rule, under about six hours stay airside, and only consider going into the city with eight or more, in daylight. The number on the ticket is not free time: you clear immigration on the way out, travel in and back, then return through security and to the gate with a real buffer. If the two flights are on separate tickets, anything that goes wrong in that chain is your problem rather than the airline's. Confirm that your passport allows you to enter that country at all, and be honest about how you will feel after ten hours in a seat.
A few hours needs almost no data
A short connection genuinely needs very little: a boarding pass, a few messages, and telling someone at home that you landed. Airport wifi normally covers that, though some networks ask you to register first, sometimes with a code sent by text, so it helps if your home number is still reachable. We sell plans for Indonesia and for Thailand, and nothing for Singapore or Malaysia, so we will not pretend to solve a stop there. If you do want mobile data on the ground, a SIM counter in the arrivals hall or a provider that covers that country will do it, and for a few transit hours it is usually not worth buying anything at all.
The part that matters is landing in Indonesia connected
The connection worth arranging in advance is the last one: data working the moment you land in Indonesia, when you want a ride, a map and your booking confirmation. That is what a Goodbars Indonesia eSIM is for, installed at home before you fly and switched on after landing at Denpasar or wherever your Indonesian leg starts. It runs on the Telkomsel network, and its validity begins on first connection rather than at purchase, so a long stop on the way does not eat into it. It also does not work during that stop, which is the honest limit: it is an Indonesia plan, and it starts earning its keep when Indonesia does.
Planning the stopover so it does not cost you a day
Keep the outbound connection tight and save the long stop for the way home, where a delay costs you a night instead of a beach day. Aim to reach Bali at a civilised hour rather than at 2am with a transfer still to do. If the stop is overnight, keep a change of clothes, chargers and anything medical in your cabin bag, and confirm that your checked luggage goes all the way through. On separate tickets, allow far more than the airline's minimum connection time. A stopover you chose is a good part of the trip; a stopover that happened to you is why people arrive in Bali already tired.
