Tool dossier

Harper

Open source grammar checker that analyzes your writing quickly while keeping your data completely private and secure on your device.

1 sources 10,283 stars Apache-2.0

Product snapshot

How the interface presents itself

Harper interface screenshot

Positioning

What this project is really offering

The goal here is to separate raw catalog facts from the sharper product shape users care about before they commit time.

About

Harper offers a refreshing approach to grammar checking by putting privacy first while delivering fast, accurate results. Unlike cloud-based alternatives that send your text to remote servers, Harper processes everything locally on your device, ensuring your sensitive documents, personal writing, and confidential information never leave your computer. This open source solution provides comprehensive grammar and style checking without the subscription fees or data collection concerns of traditional tools. The lightweight design means you get instant feedback on your writing without the delays common with online checkers. Key advantages include: Whether you're drafting emails, writing reports, or crafting creative content, Harper gives you professional-grade grammar checking while maintaining complete control over your data. Perfect for writers, students, professionals, and anyone who values both quality writing assistance and digital privacy.

Highlights

The capabilities most worth remembering

01

Complete privacy protection

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Lightning-fast analysis

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Zero cost

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Transparent code

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Cross-platform compatibility

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Offline functionality

Evidence

What backs up the editorial summary

Primary source links