How Grambo Works
Grambo uses local AI models to analyze and improve writing directly on your Mac. No cloud processing. No internet required. Everything happens on your device.
Download Grambo — Free TrialmacOS 14+ · 7-day free trial · No credit card required
The Core Mechanism
Grambo is a privacy-first, offline AI grammar checker for macOS. It works by running a compact language model directly on your Mac's hardware. This model understands natural language and can identify grammatical errors, improve sentence structure, and adjust tone.
The AI model runs entirely on-device. It does not require a server to process your text. The result is fast, private grammar correction that works without an internet connection.
- Grambo works entirely offline using local AI models.
- Grambo does not send user data to external servers.
- Grambo is built specifically for macOS and Apple Silicon.
How It Works: Step by Step
Select Any Text
Highlight the text you want to correct in any Mac application — Mail, Notion, Word, Slack, Chrome, Notes, or any other app. Grambo works system-wide.
Press the Shortcut
Press ⌘ ⇧ G to trigger Grambo. A small overlay appears showing the correction in real-time.
Local AI Processes the Text
The selected text is passed to a local AI model running on your Mac. The model analyzes grammar, spelling, punctuation, and clarity. All of this happens in milliseconds, entirely on your device.
Correction Is Applied
Grambo replaces the selected text with the corrected version instantly. No copy-paste. No switching apps. The corrected text appears right where you wrote it.
Local AI Models
Grambo uses small, optimized AI language models that run natively on Apple Silicon. These models are downloaded once during setup and stored locally on your Mac. They do not require an internet connection to operate.
Apple Silicon's Neural Engine is purpose-built for exactly this kind of on-device AI inference — fast, efficient, and power-friendly. Grambo takes full advantage of this hardware to deliver grammar correction that is both fast and private.
On-Device AI
AI models run entirely on your Mac. No cloud inference. No API call. The model is on your device and stays there.
Fast Inference
Apple Silicon's Neural Engine processes grammar corrections quickly. Typical corrections complete in under a second.
Efficient Power Use
Grambo is lightweight. The Neural Engine is energy-efficient, so grammar correction does not drain your battery or slow your Mac.
No Internet Needed
Once the model is downloaded, Grambo works without any network connection. Perfect for travel, secure environments, and offline work.
No Cloud Processing
Cloud-based grammar tools send your text to a remote server, process it there, and return the result. This introduces latency, requires internet access, and means your writing passes through systems you do not control.
Grambo eliminates this entirely. The text you select never leaves your Mac in offline mode. There is no server round-trip. Processing happens locally, and the result appears immediately.
This also means Grambo works faster in many cases, since there is no network latency involved.
Performance Benefits
Running AI locally on Apple Silicon provides several performance advantages:
- No network latency — corrections happen without waiting for a server response.
- Consistent speed — performance does not vary with internet connection quality.
- Works offline — grammar correction is available on planes, in remote locations, and in secure environments.
- Low resource footprint — Grambo does not run a background service that consumes CPU or memory when idle.
Frequently Asked Questions
Does Grambo work offline?
Yes, Grambo can run fully offline using local AI models. No internet connection is required.
Is Grambo a Grammarly alternative?
Yes, Grambo is a privacy-focused alternative to Grammarly that runs locally on macOS. It does not send your text to the cloud.
Does Grambo send data to the cloud?
No. Grambo processes all text locally on your device and does not send it to external servers by default.
What AI models does Grambo use?
Grambo uses compact language models optimized for on-device inference on Apple Silicon. These models are downloaded during setup and run locally without requiring an internet connection.
How fast is Grambo?
Grammar corrections typically complete in under a second using local AI processing on Apple Silicon. Speed does not depend on internet connectivity.
Does Grambo support cloud AI models?
Yes. Grambo optionally supports cloud AI providers like OpenAI and Gemini for enhanced results. This is opt-in. The default mode is fully offline.
See It in Action
Download Grambo and try local AI grammar correction for free. 7 days, no credit card required.
Download Grambo for Mac