Japan lets you clear customs at a self-service terminal instead of a counter. It is faster, and it has enough specific requirements that turning up unprepared puts you back in the regular line.
Everyone entering Japan must submit a customs declaration. The e-Gate changes how, not whether.
The one that catches returning visitors
2D codes from the old Customs Declaration App stopped working on 25 January 2024. If you used that app on a previous trip, the code saved on your phone is not valid.
Use Visit Japan Web instead, which now handles both the customs and immigration declarations.
What you need
An IC passport. The e-Gate reads the chip, so a passport without one cannot use the system.
The gates are available at seven international airports in Japan, so this is not yet universal. If you are landing somewhere smaller, expect the counter.
How it actually works
Complete the electronic declaration at a terminal while you are waiting for checked baggage, which is the part that makes it fast. Then walk through the gate.
At the terminal you scan your IC passport and your Visit Japan Web 2D code, and a face photo is taken for identification.
Remove masks, sunglasses, or anything covering your face before you reach the gate. This is a genuine hold-up point, and it is easy to forget when you have been wearing a mask for twelve hours.
Families
Each passenger completes the terminal procedure individually, one at a time.
The exception: a child shorter than 100 cm may pass through the gate with a family member rather than separately.
What the e-Gate does not do
It does not exempt you from inspection. Even after declaring electronically, your baggage may still be inspected by a customs officer.
The paper Customs Declaration Form also still works, printed in advance on A4 paper, if you would rather not use the electronic route at all.