The tone of the novel is satirical, ironic, and increasingly grim. Orwell begins with the simplicity of an animal fable, then steadily turns that simplicity into a bitter attack on political corruption and totalitarian power.
Early in the novella, the tone is hopeful and almost innocent because the animals believe they are building a fairer society. After they overthrow Mr. Jones, they create the Seven Commandments, ending with the clear ideal that “All animals are equal.” Boxer’s motto, “I will work harder!” also gives the farm a sincere, earnest mood at first, since he truly believes his labor will help everyone.
Irony quickly undercuts that hope. The pigs use the language of equality while taking milk and apples for themselves, moving into the farmhouse, changing the Commandments, and using Squealer to explain every act of privilege as necessary for the farm. The tone becomes sharply satirical because the animals keep accepting obvious contradictions. The clearest example comes when the original ideal of equality becomes “ALL ANIMALS ARE EQUAL, BUT SOME ANIMALS ARE MORE EQUAL THAN OTHERS.” The sentence is absurd on its face, and the absurdity of the satire makes the grimness of the animals' situation all the more obvious as they are mistreated and even executed under the pigs' regime.
By the final chapters, the tone is bleak. Boxer, the most loyal worker, is sent away in a van marked for slaughter, while the pigs profit from his death. The pigs then walk on two legs, carry whips, and make peace with the human farmers. The final image is particularly devastating: “The creatures outside looked from pig to man, and from man to pig, and from pig to man again; but already it was impossible to say which was which.” The fable’s plain style makes the ending feel even harsher, because the corruption has unfolded step by step in language simple enough for anyone to understand.
The tone of Animal Farm depends on that tension between the surface details of the story, which at first seem lighthearted and even childish due to the talking animals, and the underlying brutal political meaning that unfolds as the novella progresses. Its talking animals make the story accessible, while its irony shows how revolutionary ideals can be rewritten until oppression returns under a new name.