---
title: "Harper Offline Privacy-First Grammar Checker by Automattic"
description: "Harper is an offline, privacy-first grammar checker written in Rust by Automattic. It runs locally with sub-10ms response times, supports LSP for editor integration, compiles to WebAssembly for browser use, and provides grammar, spelling, and style checking without sending text to external servers."
verification: "security_reviewed"
source: "https://github.com/Automattic/harper"
category:
  - "Content Writing & SEO"
framework:
  - "Multi-Framework"
tool_ecosystem:
  github_repo: "Automattic/harper"
  github_stars: 10182
---

# Harper Offline Privacy-First Grammar Checker by Automattic

Harper is an offline, privacy-first grammar checker written in Rust by Automattic. It runs locally with sub-10ms response times, supports LSP for editor integration, compiles to WebAssembly for browser use, and provides grammar, spelling, and style checking without sending text to external servers.

## Installation

Choose whichever fits your setup:

1. Copy this skill folder into your local skills directory.
2. Clone the repo and symlink or copy the skill into your agent workspace.
3. Add the repo as a git submodule if you manage shared skills centrally.
4. Install it through your internal provisioning or packaging workflow.
5. Download the folder directly from GitHub and place it in your skills collection.

## Source

- [Agent Skill Exchange](https://agentskillexchange.com/skills/harper-offline-grammar-checker-automattic/)