Grammarly vs Harper

Grammarly is a writing assistant from Grammarly, founded in 2009 and now part of Superhuman. Its listed tools include proofreading, paragraph rewrites, tone suggestions, a humanizer, and AI detector agents. Style suggestions and tone detection are listed, alongside brand voice controls and team collaboration. The Free plan is free and includes 100 AI prompts per month; Pro is $12 a month with 2,000 AI prompts per member per month. Plus is listed at ₹392 INR per member per month when billed annually, and ₹1,000 when billed monthly, and is available only via local payment methods. Grammarly lists 24 supported languages, browser compatibility with Chrome, Safari, Firefox, and Edge, and mobile apps for iPhone, iPad, and Android. Desktop apps and a browser extension are also listed. Grammarly says user content is not sold, monetized for advertising, or used to train third-party models. Its SOC 2 Type 2 report covers security, privacy, availability, and confidentiality controls.

Harper is a free, open-source grammar checker that flags capitalization, spelling, awkward phrasing, and grammar errors. The maker says checks run locally, with no cloud round-trips, telemetry, or LLM in the loop, and that suggestions appear in under 10 ms. Harper is available through browser and editor extensions, a language server, a JavaScript library, a Rust crate, and native apps. Listed integrations include Chrome, Brave, Edge, Firefox, VS Code, Cursor, Obsidian, WordPress, Neovim, Zed, Helix, Emacs, and Sublime Text. Its language support covers English and British, American, Canadian, Australian, and Indian English dialects. Harper Desktop lets users toggle rules, add dictionary entries, select a dialect, and turn checking on or off per app. The desktop app is labeled beta for macOS 14 or later, and the Windows desktop app is also described as a beta; its binary was not signed at the time of the listed post. Harper is free, with no account or credit card required.