While most countries have one or a few official or nationally recognized languages, there are usually groups of individuals living in each country who speak a language other than the country's lingua franca. The size of these minority language "groups" can range from a single individual to millions of speakers, and their numbers vary from country to country.
According to Ethnologue, a database of known languages, Papua New Guinea is still the most multilingual country on the planet. There are over 820 living languages.
The linguistic diversity of Papua New Guinea can be explained in part by the country's topography: deep valleys and challenging terrain have separated tribes and clans, resulting in the evolution of various diverse tongues and dialects.
Because the country's population is only about 7 million people, it's very likely that two persons chosen at random will speak distinct mother tongues.
With 742 live languages, Indonesia is the next country with the most languages. This number has not changed from the Ethnologue record from 2021. A major element that could explain its language diversity, similar to Papua New Guinea, is its geography—Indonesia is made up of roughly 17,500 islands (although more than 7,000 of them are uninhabited).
Fun fact: Indonesian is the most widely spoken Malay dialect, with 170 million people speaking it. By comparison, around 18 million individuals speak standard Malay.
Malay is thought to have originated approximately 1000 BC on the Asian island of Borneo.
You may also hear Indonesia referred to as bahasa baku, which is Indonesia's mainstream dialect.
Because Indonesian is quite close to Malay, you will be able to communicate with people in Malaysia and Brunei if you speak it.
When compared to other widely spoken Asian languages such as Chinese, Japanese, Korean, and Thai, it is also one of the easiest to learn.
However, while it is obvious that a diverse range of languages exist, approximately 40% of the world's languages are in danger of extinction. Even in parts of the world where there is still a great deal of linguistic diversity, languages are vanishing with each generation.
Organizations such as the United Nations are actively working to promote and safeguard these endangered languages in order to fight this.
Source : Ethnologue, Weforum.org, Langoly.com