Singapore Changi (SIN): The Complete Layover Guide

Four terminals, with the free Skytrain linking Terminals 1, 2, and 3 every 1 to 4 minutes, about 4 minutes per hop, on separate airside and landside lines. Terminal 4 sits apart, connected by shuttle bus with an airside option roughly every 10 minutes. Jewel, the glass dome with the Rain Vortex waterfall, is landside next to Terminal 1, so visiting means clearing immigration. Terminal 5 broke ground in May 2025 but opens in the next decade, so ignore it.

The structural trick that makes Changi pleasant: security happens at each departure gate, not at a central checkpoint. The whole transit hall, with its gardens, shops, and snooze lounges, is open to you the moment you land. The flip side is that your gate opens for screening well before departure, and once through, you wait in the gate room.

Connections and immigration

Transferring between Terminals 1, 2, and 3 needs no immigration at all; the airside Skytrain keeps you in transit. Skytrain hours run from roughly 4:30am to past 1:30am depending on the leg, so a deep overnight transfer may mean the shuttle or a wait. Changi consistently turns tight connections that would frighten you elsewhere into nonevents, though gate level security still wants its minutes.

The lounge landscape

Roughly ten pay per use and Priority Pass lounges spread across the terminals: SATS Premier in T1, T2, and T3, Ambassador Transit Lounges in T2 and T3 with the T3 location open 24 hours and renting nap rooms, Marhaba in T3, and the Blossom Lounge in T4. The SATS Premier in Terminal 3, refurbished in 2024, is our pick of the paid entries. Airline lounges add another tier on top. Full table in the SIN lounge directory.

Sleeping at Changi

The free snooze lounges in every terminal have reclined seating and power points and run around the clock. Paid options go from nap rooms at the Ambassador Transit Lounge to the Aerotel in T1 transit and YOTELAIR in Jewel. Nobody wakes you, the lights dim, and it is genuinely safe. The full map is in the SIN sleeping guide.

Getting to the city

The MRT from the Changi Airport station reaches the center in about 30 to 40 minutes for a few Singapore dollars, transferring at Tanah Merah. First trains run at 5:31am Monday to Saturday, last connecting trains around 11:18pm to midnight. Better still, the free City Sights Tour takes about 2.5 hours past Merlion Park and Gardens by the Bay; register in T2 near gate F50 or T3 near gates A1 to A8 with a layover of roughly 5.5 to 24 hours. Entry rules depend on your passport, so verify before travel.

The small print that helps

The butterfly garden in Terminal 3 transit, the first inside any airport, is free and open to anyone airside, and it resets a tired brain better than most lounges. Terminal 2 is worth a wander even when your gate is elsewhere: it fully reopened in November 2023 after a long rebuild and is the newest interior in the main cluster.

If Jewel tempts you, know the trade. YOTELAIR there rents cabins from 4 hour blocks and the Changi Lounge keeps nap pods by the hour, but all of it sits landside, so the visit costs you immigration twice plus gate security on the way back. With less than 4 spare hours, the gardens and snooze lounges airside give you most of the magic for none of the queue.

One timing note: the Skytrain winds down in the deep night hours depending on the leg, so a transfer landing after 1:30am may mean the shuttle bus or a short wait. The snooze lounges, helpfully, never close.

Do I go through immigration when changing terminals at Changi?

Not between Terminals 1, 2, and 3: the airside Skytrain links them inside the transit area, every 1 to 4 minutes, about 4 minutes per hop. Terminal 4 is off the Skytrain and connected by shuttle bus, with an airside option. You only clear immigration if you choose to enter Singapore, for example to visit Jewel.

Where can I sleep for free at Changi airport?

Free snooze lounges with reclined seating and power points sit in the transit areas of all four terminals, open around the clock. For privacy, the Aerotel in Terminal 1 transit and the Ambassador Transit Hotels in Terminals 2 and 3 rent rooms in short blocks, and the Ambassador Transit Lounge in Terminal 3 has paid nap rooms 24 hours a day.

Is the free Singapore tour still running in 2026?

Yes. The free City Sights Tour runs about 2.5 hours past Merlion Park and Gardens by the Bay, with registration counters in Terminal 2 near gate F50 and Terminal 3 near gates A1 to A8. You need a layover of roughly 5.5 to 24 hours and an eligible onward ticket. Verify before travel, as slots and rules change.

Is Jewel airside or do I need to clear immigration?

Jewel is landside, linked to Terminal 1. To see the Rain Vortex waterfall you clear Singapore immigration first, so check your visa situation and verify before travel. Allow at least 3 spare hours beyond your boarding buffer for the round trip and gate level security.

Can I leave Changi airport during a layover?

Often yes, since many nationalities enter Singapore visa free, but verify before travel. The MRT runs from the airport in about 30 to 40 minutes to the center for a few Singapore dollars, with a transfer at Tanah Merah. First trains leave at 5:31am Monday to Saturday; last connecting trains depart around 11:18pm to midnight.

How early do I need to be at my gate at Changi?

Earlier than the airport feels like it demands. Security screening happens at each departure gate rather than centrally, and gates typically open well before departure for screening. Treat the posted gate open time as real, and add Skytrain time if your gate is in another terminal.