晚上好(wǎn shàng hǎo) - good evening in Mandarin

晚上好 (wǎn shàng hǎo) is the standard greeting for good evening, used from roughly early evening onwards. It is built from 晚上 (wǎn shàng, "evening") plus 好 (hǎo, "good"), the same pattern as 早上好 (zǎo shàng hǎo, "good morning").

It sits a register above 你好 (nǐ hǎo, "hello") without being especially formal: fine for greeting a teacher, a shopkeeper, or a group of friends arriving somewhere after dark. Compare it with 晚安 (wǎn ān, "good night"), which is a farewell for going to bed, not a greeting on arrival - mixing the two up is a common learner slip.

An English speaker's instinct is to reach for "good evening" only in stiff, formal contexts, but 晚上好 (wǎn shàng hǎo) is used far more casually in Mandarin, including by children greeting relatives or hosts opening a livestream.