The history of idli dates back centuries and is closely associated with the cuisine of South India, particularly the states of Tamil Nadu and Karnataka. While the exact origin of idli is not known, it is believed to have originated in present-day Tamil Nadu.

Idli is mentioned in ancient Indian texts like the 10th-century work called "Manasollasa" by King Somesvara III of the Western Chalukya Empire. The text describes a dish called "iddarika" made by steaming fermented black lentil and rice batter. This is considered to be an early reference to idli.

Idli gained popularity over time and became a staple breakfast item in South India. The dish was traditionally made using a combination of rice and black lentils (urad dal). The rice and lentils are soaked, ground into a smooth batter, and fermented overnight. The fermentation process gives idli its characteristic fluffy texture and tangy flavor.

The idli batter is poured into specially designed molds or plates called "idli plates" and then steamed until cooked. The resulting idlis are soft, spongy, and easily digestible. They are typically round and have a mild, slightly sour taste.

Idlis are traditionally served with a variety of accompaniments, including coconut chutney, sambar (a lentil-based vegetable stew), and various types of chutneys or podis (spice powders).

Over time, idli has gained popularity beyond South India and is now enjoyed throughout the country and even internationally. It is considered a healthy and nutritious dish due to its low-fat content, fermentation process, and use of easily digestible ingredients.

Today, idli has also undergone some variations to cater to different preferences and dietary needs. There are variations like rava idli (made using semolina or cream of wheat), oats idli (made using oats), and even stuffed idlis with various fillings.

Overall, idli holds a significant place in Indian cuisine and continues to be a beloved and widely consumed dish, both in its traditional form and with modern adaptations.