Heidi is a timeless book where the virtuous characters ultimately live "happily ever after." In today's unpredictable world, where both news and fiction often lean towards harsh realism, it's comforting to encounter a tale where the good are rewarded and love and honesty prevail. Modern readers might find some elements of the story slightly exaggerated. Heidi is almost excessively joyful, Peter is portrayed as overly simple-minded, and the grandfather seems too wise and kind beneath his gruff exterior to be entirely believable. Nevertheless, readers form a deep connection with these characters and become engrossed in their journey.

Originally written in German, the book was first translated into English in 1884. It tells a straightforward story of the love between a girl and her grandfather, the joy of helping others, the beauty of nature, and a reverence for God. The antagonists, Aunt Dete and Fraulein Rottenmeier, fail to recognize Heidi's innate goodness, the girl from the mountains. Heidi's home in the Alps is depicted as a perfect retreat, far removed from modern life's complications. The book's lasting appeal stems from its lively characters and universal themes. As Clifton Fadiman notes in his afterword to the Macmillan Classics edition of Heidi,, ever since the first English translation in 1884, "year after year, it has kept its place in the hearts of young readers, especially girls." Currently, there are fifteen editions in print, three of which are simplified versions. The key to its enduring success is that Heidi brings happiness to its readers.