What is Grambo?
Grambo is an AI-powered grammar and writing assistant built exclusively for macOS. It lives in your menu bar and works system-wide — there is nothing to paste text into and no browser extension to install. Select any text in any app, press a hotkey, and Grambo replaces it with a corrected version, right where you typed it.
The app supports three distinct modes: a managed cloud service, your own AI provider API key, and fully on-device Local AI. Pick the approach that fits your privacy needs, your existing tools, and your budget.
Which setup is right for you?
Here is a quick comparison of the three modes before you download anything:
| Grambo Cloud | BYOK | Local AI | |
|---|---|---|---|
| Best for | Zero setup, fastest start | Existing AI API key holders | Privacy, offline use |
| API key needed | No | Yes (Gemini, Claude or OpenAI) | No |
| Internet required | Yes | Yes (except local custom server) | No, after model download |
| Where your text goes | Grambo's cloud endpoint | Your chosen AI provider | Stays on your Mac |
| Extra cost | Included in plan | Provider API usage charges | None |
| Plan required | Monthly only | Trial, then Monthly or Lifetime | Trial, then Monthly or Lifetime |
| Setup effort | Lowest | Low–medium | Medium (~2 GB download) |
| Works in free trial | ✗ No | ✓ Yes | ✓ Yes |
Grambo Cloud
Subscribe for $2.99/month and you're done. No API keys, no model downloads. Best if you want to be correcting text within five minutes.
Bring Your Own Key (BYOK)
Use your existing Google Gemini, Anthropic Claude, or OpenAI API key. Grambo calls the provider directly from your Mac with no Grambo server in between. Covered by the 7-day free trial.
Local AI
Run a small AI model entirely on your Mac via Ollama. Text never leaves your machine. Covered by the 7-day free trial. Requires downloading about 2 GB and running Auto Setup once.
Download & Install Grambo
System requirements
- macOS 14.4 or later
- An internet connection for Grambo Cloud and BYOK. Local AI works fully offline after the model is downloaded.
- For Local AI: about 4 GB RAM for Llama 3.2 3B, or less for Qwen3 1.7B.
Installation steps
Download Grambo
Go to gramboapp.com and click the Download button to get the latest version.
Open the .dmg file
Double-click the downloaded .dmg file to mount it.
Drag Grambo to Applications
The disk image shows a drag-to-Applications background. Drag Grambo into the Applications folder.
Open Grambo from Applications
Launch Grambo from your Applications folder. Because the app is signed with a Developer ID and notarized by Apple, macOS will open it without a security warning.
Grambo is a menu-bar app with no Dock icon. After launch, look for the Grambo icon in the menu bar. Left-click it to open the status popover; right-click for Fix Grammar, Settings, and Quit.
Free trial: A 7-day free trial starts on first launch. The trial covers BYOK and Local AI. Grambo Cloud requires an active monthly subscription — the trial does not apply to Cloud.
Grant Accessibility Permission (Required)
Grambo needs Accessibility permission to read your selected text and replace it with corrected text in other apps. Without this permission, the hotkey will not work.
Open the permission prompt
Grambo will prompt you at first launch. If you missed it, open Settings → Permissions and click Enable.
Turn Grambo on in System Settings
Go to System Settings → Privacy & Security → Accessibility and toggle Grambo on.
Confirm in Grambo
Return to Grambo. The Permissions screen should show "Permission granted".
First-Launch Onboarding
When you first open Grambo, a three-step onboarding window walks you through the initial configuration.
Step 1 — Choose your setup
The "Welcome to Grambo" screen asks "Choose how you'd like to use Grambo for grammar corrections". Pick one of three cards:
- Grambo Cloud (labelled Recommended)
- Your API Key (BYOK)
- Local AI (Privacy First)
Click Continue to proceed.
Step 2 — Path-specific setup
This screen depends on your choice. Details for each path are in the sections below. Click Next when done.
Step 3 — All Set!
The "All Set!" screen shows the quick-start strip: Select text → Press ⌘⇧G → Get fixed text. Choose your default Language (Detect Language by default) and Tone (Standard by default), then click Get Started.
You can change your service type at any time in Settings → General → Service Type. You are never locked into the choice you make during onboarding.
Setup A — Grambo Cloud
Grambo Cloud is the simplest path. Grambo's own hosted service handles grammar correction — no API key, no model download. All you need is an active monthly subscription.
Heads up: Grambo Cloud requires a Monthly subscription ($2.99/month). Lifetime license holders should use BYOK or Local AI — attempting to use Cloud with a Lifetime license shows the message "Grambo Cloud is only available for monthly subscription users".
Steps
Choose Grambo Cloud in onboarding
On Step 1 of onboarding, select the Grambo Cloud card and click Continue.
Start checkout
On Step 2 ("Grambo Cloud Setup"), click the Monthly Subscription card. The checkout page opens in your browser.
Complete the purchase
Finish the purchase and copy the license key from the confirmation email or checkout confirmation page.
Activate your license
Open Grambo → Settings → License, paste the key into the field, and click Activate.
Verify the service type
In Settings → General, confirm that Service Type is set to Grambo Cloud.
Fix your first sentence
Select any text in any app and press ⌘⇧G.
Pricing
- Monthly subscription — $2.99/month. Includes Grambo Cloud.
- Lifetime license — currently $14.99 (regularly $39.99). Does not include Grambo Cloud, but works with BYOK and Local AI.
Already have a license key? Skip checkout. Finish onboarding, go to Settings → License, paste the key, click Activate, then switch Service Type to Grambo Cloud.
Setup B — Bring Your Own Key (BYOK)
BYOK lets you use your own API key from Google Gemini, Anthropic Claude, or OpenAI. Grambo calls the provider directly from your Mac — there is no Grambo server in between. Your keys are stored locally in app preferences and only sent to the provider you select. BYOK is covered by the 7-day free trial.
Supported providers
- Google Gemini — get a key at aistudio.google.com/apikey
- Anthropic Claude — get a key at console.anthropic.com
- OpenAI — get a key at platform.openai.com/api-keys
- Custom Server — any OpenAI-compatible endpoint (see below)
You pay your AI provider for API usage. Grammar correction requests are small and use low-cost models, so charges are typically minimal.
Steps
Choose Your API Key in onboarding
On Step 1, select the Your API Key card and click Continue.
Get your API key
On Step 2 ("Add Your API Keys"), click the link icon next to a provider to open its key page. Create a key and copy it.
Paste the key
Paste the key into the matching field. Use the eye icon to show or hide it. At least one key is required to continue.
Finish onboarding
Click Next and then Get Started on the "All Set!" screen.
To add or change keys later: Settings → General → API Keys → paste key → Save API Keys. To switch provider or model: Settings → General → AI Provider & Model.
The first provider with a saved key is selected automatically (order: Gemini → Claude → OpenAI). If you select a provider without a saved key, Grambo shows "API Key Required — add your key and save it before selecting this provider".
For a step-by-step walkthrough on creating keys for each provider, see the API keys help article.
Optional: Custom Server (advanced)
BYOK also supports any OpenAI-compatible endpoint such as LM Studio, vLLM, LiteLLM, Azure OpenAI, or Ollama in OpenAI-compatibility mode.
In Settings → General → Custom Server (visible in BYOK mode), select Custom Server as the provider and fill in:
- Server URL — e.g.
https://localhost:1234/v1/chat/completions - API Key — optional; leave blank for local servers
- Model Name — the model ID you want to use
Grambo automatically appends /chat/completions to your URL if it is missing. A live "Will call: …" hint shows the final endpoint as you type. More details: Custom Server URL help.
Setup C — Local AI (Offline)
Local AI runs a small language model directly on your Mac using Ollama. Text never leaves your machine, no internet connection is needed after the model is downloaded, and there are no per-request charges. Covered by the 7-day free trial.
Choose your model
- Llama 3.2 3B — about 2 GB download, needs ~4 GB RAM. Better accuracy. Recommended for most users.
- Qwen3 1.7B — about 1.4 GB download, lighter on RAM. A good choice for older Macs or multilingual text.
Important: Onboarding only saves your model preference — it does not download anything. You must complete Auto Setup in Settings after onboarding.
Steps
Choose Local AI in onboarding
On Step 1, select the Local AI card and click Continue.
Pick your model
On Step 2, choose Llama 3.2 3B or Qwen3 1.7B and finish onboarding (Next → Get Started).
Open Local AI Setup in Settings
Go to Grambo → Settings → General → Local AI Setup.
Click Auto Setup
Grambo will check whether Ollama is installed, install it via Homebrew if needed (or open ollama.ai for manual install), start the Ollama service, then download your chosen model with a progress bar. A Cancel Download button appears while downloading.
Wait for all three checks
Wait until the status rows show check marks for Ollama installed, Ollama running, and Model downloaded.
Fix your first sentence
Select any text and press ⌘⇧G. Grammar correction runs entirely on your Mac.
If the Ollama service won't start, Grambo suggests running ollama serve in Terminal. If you cancel a download, pick a different model and run Auto Setup again.
More details: Local AI help article.
Your First Fix & Hotkeys
Basic usage
- Select any text in any app — Mail, Notes, Slack, a browser field, anything.
- Press ⌘⇧G.
- The selected text is instantly replaced with the corrected version.
Default keyboard shortcuts
All shortcuts are configurable in Settings → Keyboard Shortcut.
| Shortcut | Action |
|---|---|
| ⌘⇧G | Fix grammar with current tone and language |
| ⌘⇧1 | Shortcut 1 — Formal tone by default |
| ⌘⇧2 | Shortcut 2 — Casual tone by default |
| ⌘⇧3 | Shortcut 3 — Professional tone by default |
Each of the three extra slots (⌘⇧1–3) can be assigned to a custom prompt instead of a tone preset, and each can be individually enabled or disabled.
Tones and languages
- Tones: Standard, Casual, Friendly, Formal, Professional, Academic
- Language: Detect Language (default), plus English, Spanish, French, German, Japanese, Hindi, and many more
More features worth knowing
- Custom Prompts — write your own instructions (translate, simplify, rewrite in a specific style)
- Names to Remember — add proper names so the AI never misspells them
- History — the last 50 fixes with word-level before/after comparison
- Insights — usage stats and charts
- Sound feedback — distinct sounds for start, success, and error
- Auto-updates — checks once a day via Sparkle; manual check in Settings → Updates
Troubleshooting & FAQ
| Problem | Likely cause | Fix |
|---|---|---|
| Hotkey does nothing | Accessibility permission missing | Settings → Permissions → Enable, then turn Grambo on in System Settings → Privacy & Security → Accessibility |
| Can't find the app | No Dock icon — it's a menu-bar app | Look for the Grambo icon in the menu bar |
| "License key required" (Cloud) | No license activated | Settings → License → paste key → Activate |
| "Grambo Cloud only available for monthly subscription users" | Lifetime license is active | Use BYOK or Local AI with Lifetime, or switch to Monthly plan |
| "Your trial has expired…" | 7-day trial ended | Purchase a Monthly or Lifetime license at gramboapp.com |
| "API Key Required" alert | Provider selected without a saved key | Settings → General → API Keys → add key → Save API Keys |
| Fix fails with BYOK | Invalid key, exhausted credits, or wrong model ID | Re-check the key and billing on the provider's site; clear the Custom model field to fall back to the default |
| Local AI errors or timeouts | Ollama not running or model not downloaded | Run Auto Setup again in Settings → General → Local AI Setup, or run ollama serve in Terminal |
| Local AI is slow | Large model on older Mac | Switch to Qwen3 1.7B in Local AI Setup |
| License activation limit reached | Key used on too many devices | Contact support@gramboapp.com |
Frequently asked questions
Does Grambo work completely offline?
Yes — with Local AI. Once the model is downloaded during Auto Setup, grammar correction runs entirely on your Mac with no internet connection needed.
Is my text stored or sent anywhere?
It depends on the path you choose. With Grambo Cloud, text is processed through Grambo's cloud endpoint. With BYOK, text is sent to your chosen AI provider. With Local AI, nothing leaves your Mac.
Can I switch between Cloud, BYOK, and Local AI later?
Yes. Go to Settings → General → Service Type at any time to switch modes.
Can I save more than one provider key?
Yes. You can save keys for Gemini, Claude, and OpenAI simultaneously and switch between them in Settings → General → AI Provider & Model.
Which Macs are supported?
Any Mac running macOS 14.4 or later.
Does Grambo update itself?
Yes. Grambo checks for updates automatically once a day using Sparkle. You can also trigger a manual check in Settings → Updates.
Where can I get help?
Visit the Grambo help centre or email support@gramboapp.com.
Ready to fix your first sentence?
Download the latest version of Grambo and start your 7-day free trial. No credit card needed for BYOK or Local AI.
Download Grambo for Mac