Hemingway Editor highlights lengthy, complex sentences and common errors in your writing. Yellow marks sentences to shorten or split, red indicates dense and complicated sentences, purple suggests simpler words, and blue flags adverbs, passive voice, and weak phrases. The Hemingway Editor Plus service uses AI to fix these highlights automatically, features an advanced grammar checker, and lets you change tone or style with AI tools. Paste text to edit or use Write mode for distraction-free composition.