What’s the longest river in the world?

Whether the Nile or the Amazon is the world's longest river is a subject of ongoing debate among experts [1].

The answer often depends on how you measure a river, including where you define its source and how you track its path to the sea [1, 3]. Because of these different methodologies, you will find reputable sources that cite either the Nile or the Amazon as the record holder [1, 3].

• The Nile: Long traditionally cited as the longest river in the world, located in eastern and northeastern Africa [3].
• The Amazon: Also widely recognized as the longest, particularly when measuring from its most distant headwaters in the Andes [3].

Because there is no universal consensus on the exact measurement techniques, it remains one of the great open questions in geography [1].