Grammar Guru vs Harper
Grammar Guru
grammarguruai.com
Harper
writewithharper.comSide by side
| Figure | Grammar Guru | Harper |
|---|---|---|
| Price from | $1/mo | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | Yes |
| Web | Yes | Yes |
| Windows | Yes | Yes |
| macOS | Yes | Yes |
| Linux | Yes | Yes |
| iOS | — | Yes |
| Android | — | Yes |
| API | — | Yes |
| Plans published | 4 | 2 |
| Spec score · Grammar checkers | 9.3 (#5) | 8.9 (#19) |
| API and SDKs | The maker pages reviewed describe browser extensions and a Windows app but do not provide public API or SDK documentation. | Developers can integrate harper.js as a JavaScript library, harper-core as a Rust crate, or harper-ls through the Language Server Protocol. |
| Browser extension | Yes | Yes |
| Desktop app | Yes | Yes |
| Free plan | Yes | Yes |
| Integrations | The maker lists Gmail and Google Docs support for Chrome and Outlook and Office 365 support for Edge. | The maker lists browser and editor extensions, a language server, a JavaScript library, a Rust crate, and native apps. |
| Privacy | The privacy policy says submitted text is processed in real time and discarded after suggestions, while account and usage information may be retained. | Checks run locally; the maker says Harper has no cloud round-trips, telemetry, or LLM in the loop. |
| Rating on Chrome Web Store | 3.0 out of 5 from 2 ratings. | 4.2 out of 5 from 128 ratings |
| Speed | The home page says suggestions appear instantly without slowing down the browser or workflow. | Harper says it provides suggestions in under 10 ms. |
| Style suggestions | Yes | Yes |
| System requirements | The download page specifies Chrome 88 or later on Windows, macOS, or Linux, Edge 88 or later on Windows or macOS, and Windows 10 or later with a 64-bit processor for the app. | The maker says Harper needs no GPU or special additional memory; the desktop application currently supports macOS 14 or later. |
Plans
Grammar Guru
- FreeFree
- Standard$1 a month
- Windows App$1 a month
- EnterprisePriced on request
In their own words
Grammar Guru
Grammar Guru has no write-up on Specifiction yet; its figures are above.
Harper
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.