Farthest and furthest are superlative adjectives or adverbs. They are the irregular superlative forms of far. We use them to talk about distance. There is no difference in meaning between them. Furthest is more common than farthest: The furthest galaxies are about three thousand million light years away.

Farthest refers to the greatest distance measurable, while furthest can denote the greatest distance, degree, or extent, allowing for metaphorical use. Key Differences Farthest and furthest are often used interchangeably but tend to have nuanced differences.

Furthest is often used when discussing non-physical distances, such as in time, degree, or abstract concepts. Farthest, on the other hand, is typically reserved for tangible distances that can be measured or observed. 8 In literature or conversation, "furthest" might describe the extent of one's imagination or the depth of an emotion.