Harper: The Offline, Privacy-First Grammar Checker Built in Rust
Why This Matters
Most grammar checkers require an internet connection, send your text to a remote server, and often come with a subscription fee. Harper flips the script—it’s open-source, offline-first, and privacy-focused, making it ideal for developers, writers, or anyone who values speed and data security. Plus, it’s built in Rust, so it’s fast and reliable.
What It Does
Harper is a local grammar checker that analyzes text without sending it to the cloud. It supports:
- Multiple document formats (Markdown, HTML, Typst, etc.)
- Fast, offline processing (no latency, no tracking)
- Custom rules (so you can tweak its suggestions)
It’s not just a spellchecker—it understands grammar, style, and even code comments (handy for devs writing docs).
Why It’s Cool
- Privacy by Default – Your text never leaves your machine.
- Rust-Powered Performance – Instant feedback, even on large documents.
- Extensible & Open – Modify rules or integrate it into your workflow.
- Works Everywhere – CLI, WASM, and even a VS Code extension (in development).
How to Try It
- Install via CLI (if you have Rust):
cargo install harper-cli - Use the web demo: writewithharper.com
- Check the GitHub repo for advanced setups: github.com/Automattic/harper
Final Thoughts
Harper is a rare find—a no-BS, developer-friendly tool that respects privacy without sacrificing usability. If you write docs, code comments, or just want a faster alternative to Grammarly, give it a spin. The fact that it’s open-source means you can tweak it to your needs (or contribute to make it even better).
Who’s it for? Devs, technical writers, or anyone tired of cloud-dependent tools. Worth a look. 🚀