Kaipen (Lao: ໄຄແຜ່ນ, romanized: khai phaen, pronounced [kʰáj.pʰɛ̄n]) is a Laotian snack made of fresh water green algae, garlic, vegetables, and sesame seeds.

Kaipen is produced in northern Laos and is especially popular in the city of Luang Prabang.

It is washed and pounded thoroughly for maybe a couple of hours, generally in fresh water outside of the river and then set into cubes.

A boiled, flavoured liquid including water, green and black olives and tamarind is then poured over it.

[1] Kaipen is rich in vitamins and minerals and tastes similar to nori but is slightly more sweet, bitter, and aromatic.