Overview
GrammaticAI is an AI writing assistant for macOS that rewrites and improves text instantly with a single keyboard shortcut in any app. It fixes grammar, controls tone with casual and formal modes, and translates across languages — each with its own customizable shortcut. Supports multiple AI providers including OpenAI, Claude, Gemini, and DeepSeek, with the option to use your own API keys or the built-in service. Text is replaced in place with native undo support via Cmd+Z.
Pricing: Free (10/day) | Premium: $69/year | Pro: $29/year (BYO API key)
Architecture: Apple Silicon, Intel
Key Features
- System-wide text improvement with a global keyboard shortcut
- Grammar correction and clarity improvements
- Casual and formal tone modes per language (add Shift to toggle)
- Multiple output languages with per-language shortcut keys
- Supports OpenAI, Claude, Gemini, and DeepSeek AI providers
- Works in any macOS app — Slack, Gmail, Notion, browsers, and more
- Instant in-place text replacement with native Cmd+Z undo
- Free tier with 10 improvements per day, no account required
- Premium plan with no API key needed, Pro plan for BYO API keys
- Private by design — text is not stored or shared
