Harper Brings Offline Grammar Checking to Rust

Harper is an open-source English grammar checker written in Rust that runs offline and keeps text private. It targets writers and developers who want fast grammar feedback without sending documents to a cloud service. The project focuses on practical suggestions, local processing, and integrations that can fit into everyday editing workflows.

Devtools grammar rust privacy writing-tools

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Harper Brings Offline Grammar Checking to Rust

Harper is a privacy-first grammar checker that runs locally instead of sending text to a remote service. Built in Rust, it aims to give fast English writing feedback while keeping drafts, notes, and code comments on the user's machine.

Why it matters

Many grammar tools depend on cloud processing and broad suggestions. Harper takes a different path: offline checks, open-source code, and practical edits that writers can inspect and trust.

Good fit for

- Developers writing documentation and comments
- Writers who want local grammar checks
- Teams that care about privacy and open-source tooling