harper
SHA-256Harper is a fast, offline English grammar checker built with Rust. It prioritizes privacy by running entirely on your device, unlike cloud-based alternatives like Grammarly, and is much lighter than LanguageTool, using under 1/50th of its memory.
Smart Download
Download Download Version
v2.6.0 · 14.1 MB
A fast, offline, privacy-first English grammar checker that runs on your device with zero cloud dependency.
Core Features
- 100% offline, no data sent to servers
- Millisecond-level linting, minimal memory footprint
- Integrates with VS Code, Neovim, Helix, Emacs, Zed, and more
- Runs in the browser via WebAssembly
- Open source, built with Rust for performance
What It Can't Do
- •Currently English only; may raise false positives on mixed-language text
- •Complex sentences and domain-specific terms might be misflagged
- •Not a replacement for professional writing tools; use as a helpful assistant
Use Cases
- Everyday English writing with instant grammar feedback
- Seamless integration into your favorite code editor or note-taking app
Detailed Introduction
Harper is an English grammar checker designed with a focus on speed, privacy, and simplicity. Unlike Grammarly, which sends your text to remote servers, Harper runs entirely offline, ensuring your writing stays private. It is also dramatically more efficient than LanguageTool, requiring far less memory and processing documents in milliseconds rather than seconds. Built in Rust and available as a language server, Harper integrates seamlessly with editors like VS Code, Neovim, Helix, Emacs, and Zed, and can even run in the browser via WebAssembly. While currently supporting only English, its architecture is extensible for other languages. Contributions are welcome.
Tags
Getting Started
Download installer
Click the button above to download the installer for your system
Install the software
Double-click the downloaded installer and follow the prompts
Install the Harper extension from the VS Code marketplace
Open any English text file and see grammar suggestions automatically
Click underlined words to view and apply corrections
- Install the Harper extension from the VS Code marketplace
- Open any English text file and see grammar suggestions automatically
- Click underlined words to view and apply corrections
SHA-256 checksum verified
Checksum extracted from GitHub official Release page
SHA256 Checksum
6f57e1dfb43e39a79d4da2df8e1d6e5b91f9fa3133761938c61b208b471e5860This checksum is extracted from the GitHub Release page. Verify file integrity after download.
All SHA-256 checksums on this platform are extracted from the project's official GitHub Release page, without any modification. You can independently verify them on the GitHub Releases page.
Open Source Transparency
View GitHub SourceUninstall Info
Remove the Harper extension from VS Code's extension manager, or follow the editor-specific docs to uninstall the language server.
No Extra Dependencies
Ready to use after download. No additional runtime required.
Similar Projects
Immich
High performance self-hosted photo and video management solution with automatic backup, AI search, facial recognition, and multi-user support.
syncthing
A continuous file synchronization program that syncs files between devices securely and automatically, with no central server.
uBlock Origin
uBlock Origin is a wide-spectrum content blocker for Chromium and Firefox that is CPU and memory efficient. Blocks ads, trackers, miners, and malware out of the box.