Methyl orange is widely used as a pH indicator in various chemical and biological applications. It is particularly useful in titrations to determine the acidity or alkalinity of a solution. In acidic conditions (pH below 3.1), it appears red, while in alkaline conditions (pH above 4.4), it turns yellow. This distinct color change makes it a valuable tool for identifying the endpoint in acid-base titrations, especially in the pH range of 3.1 to 4.4.

In educational laboratories, it is commonly employed to teach students about pH and titration techniques. It is also used in environmental testing to assess the pH of water samples, which is crucial for monitoring water quality. Additionally, methyl orange finds applications in the textile industry for dyeing fabrics and in research laboratories for studying chemical reactions that involve pH changes. Its reliability and ease of use make it a popular choice for quick and accurate pH determination.