Why did the piano replace the harpsichord as a common keyboard instrument in the 18th century?

The piano replaced the harpsichord as the dominant keyboard instrument primarily due to its ability to produce dynamic gradation, a feature the harpsichord lacked.1

While the harpsichord produces sound by plucking strings, which results in a uniform volume regardless of how hard a key is pressed, the piano—invented by Bartolomeo Cristofori around 1709—utilizes a hammer action. This mechanism allows the player to control the volume of the sound—ranging from soft (piano) to loud (forte)—based on the pressure applied to the keys.23145

By the mid-18th century, the piano’s capacity for this expressive dynamic range led to its growing popularity over the harpsichord. As composers like Wolfgang Amadeus Mozart began writing specifically for the piano, a distinctively pianistic style emerged, further cementing the instrument's role as the preferred medium for chamber music, concerti, and salon music. Ultimately, the harpsichord was overwhelmed by the piano's versatility and its ability to provide the nuanced emotional expression required by evolving musical styles.13