Almost all countries' passports can enter without applying for a visa in advance.

Remember to have your return e-ticket (hard copy or on mobile phone) ready to be shown to the immigration officer.

A USD20 departure tax and USD30 "green fee" is payable in cash or credit card before going through passport control when departing.

A very-well maintained, clean and comfortable lounge with shower, snacks, lying chairs is located right next to the airport hall open 24/7, it's a good place to take a rest if you are on an early/late flight which is common getting out of Palau. Standard price is USD50, but I got USD20 for 6-hou, just ask the reception.