Which river is longer, the Nile River or the Amazon River?

The Nile River is widely considered the longest river in the world, with a length of approximately 4,132 miles (6,650 km).1

While some researchers have argued that the Amazon River is longer—proposing measurements of up to 4,345 miles (6,992 km) based on different interpretations of its source and mouth—these claims remain a subject of significant scientific debate. Because the precise length of both rivers is difficult to determine due to complex, variable streambeds and differing methodologies for identifying starting and ending points, the title of the world's longest river is often contested. However, the Nile remains the most widely accepted answer in the scientific community.231