Perfect Grammar in Every Application

Open source AI-powered grammar checker that works across all Windows applications. Simply highlight text and get instant corrections using your OpenAI API key - no subscriptions required.

Download for Windows

Instant Grammar application interface showing OpenAI API configuration, status, and usage instructions

Powerful Features for Perfect Writing

Advanced AI technology that understands context and provides intelligent suggestions

Instant AI Corrections

Get real-time grammar, spelling, and style suggestions powered by advanced AI

Universal Compatibility

Works across all Windows applications - Word, browsers, email clients, and more

Privacy First

Your text stays on your device. No data is sent to external servers

Open Source & No Subscriptions

100% Open Source

View the source code, contribute, or customize the application to your needs.

View on GitHub

No Subscription Required

Simply input your OpenAI API key and start using the app immediately. Pay only for what you use through OpenAI.

One-time download, lifetime use

How It Works

Three simple steps to perfect grammar in any Windows application

Highlight Text

Select any text in any Windows application using your mouse or keyboard

AI Analysis

Our AI instantly analyzes the text for grammar, spelling, and style issues

Automatic Corrections

Corrections are applied automatically, no need to click or press any keys

Ready to Improve Your Writing?

Download Instant Grammar for Windows and start writing with confidence

Instant Grammar

Version 1.0.1 • Windows 10/11

Download Free (33 MB)

✓ Open source • ✓ No subscription required • ✓ Use your own OpenAI API key

System Requirements: Windows 10 or later, 35MB free space