The grammar checker that works offline
Check and fix grammar directly in the Mac apps you already use. Fast, private, and fully offline.
v1.35.1
macOS 14+
Full-featured 7-day free trial
Writing That Never Leaves Your Mac
Unlike cloud-based tools, Refine processes everything locally using advanced AI models.
See how offline grammar checking worksEvery Word Stays Local
Processed entirely on your device, with nothing uploaded or monitored.
Lightning Fast
Local processing delivers instant results without internet delays.
Always Available
Works offline in flights, coffee shops, or anywhere you write.
Don't Just Fix It. Understand It.
Refine doesn't just correct your mistakes, it explains them. Click "Explain" and get a clear, AI-powered explanation for any suggestion.
Understand the "Why"
Get explanations for every suggestion to understand the reasoning behind it.
Learn & Grow
Improve your writing skills over time by understanding grammar rules and stylistic choices.
Contextual Insights
Explanations are tailored to your specific text and context, not just generic rules.
More Than a Grammar Checker
Everything you need to write clearly and quickly
One Editor for Everything
Send any text to the Floating Editor with a shortcut, then rewrite it with presets like Professional or Concise, translate it, or have it read aloud.
Snippets
Type \ anywhere to pull up your saved snippets, keep typing to filter, and hit return to expand them in place.
Customize with Prompts
Steer each check in your own words.
“Keep informal expressions, colloquialisms, and abbreviated terms unchanged.”
“Use formal language, avoid contractions, and maintain a professional tone.”
Flexible Checking Modes
Choose how and when suggestions appear.
Suggestions appear as you type
Can auto-pause while on battery
Checks only when you press your shortcut
Keyboard Shortcuts
Trigger every action with keys you choose.
Want More Power? Just Bring Your Own Key
While our local models handle most tasks brilliantly, you can connect your own API keys for access to the most advanced AI models.
- Requests go straight to the provider — no proxy, no middleman.
- Keys live in your macOS Keychain, never on our servers.
- Switch between local and cloud models with one click.
Plays Nice with Your Favorite Apps
No setup needed. Just start writing and get instant grammar suggestions.
And many more applications across macOS
Not Just Apps. Plugins Too.
Each plugin connects directly to Refine on your Mac. No cloud, fully offline.
Don't see your tool? Build your own integration with the open Refine protocol.
Works in Your Language
Grammar checking for 50+ languages and regional dialects.
English
German
French
Spanish
Portuguese
Chinese
Also supports
Simple, transparent pricing
No monthly subscriptions. No hidden fees. Just a one-time payment for lifetime access.
Compare Refine with other grammar checkersLifetime license
Includes all current features and all future updates.
What's included
- 100% private
- Offline grammar checking
- Offline fluency refinement
- Offline rewriting
- Offline AI explanations
- Offline text-to-speech
- Offline translation
- Custom AI prompts
- Customizable appearance
- Works across apps and websites
- Text snippets
- Works in 50+ languages
- Bring your own key
- Use on up to 1 device
- No monthly subscription
- No extra token fees
Lifetime
Pay once, own it forever
Lifetime access for one device
Tax included
30-day money-back guarantee
Secure payment via Stripe
What's New
Latest Updates
Check out the new features and improvements in the latest version.
Version 1.35.1
Released 3 days ago
Bug Fixes
- Fixed an issue where an already downloaded model could be reported as incomplete or corrupted
Frequently asked questions
Can't find the answer you're looking for? Feel free to send us an email at support@refine.sh
- Is my data truly private?
- Yes, absolutely. Your documents, text, and writing never leave your Mac. We don't collect, store, or transmit any of your personal content. All processing is performed locally using offline generative AI models that run directly on your machine. Once the model is downloaded, Refine works entirely offline. If you'd like, you can even use a firewall app to block its internet connection completely.
- What apps does it work with?
- Works with most macOS apps including Mail, Messages, Safari, Chrome, Pages, Word, Slack, Notion, and many more. For apps that don't support macOS accessibility features (where even VoiceOver can't read the content), you can set up a keyboard shortcut to check your writing with a floating editor without interrupting your work.
- What about system requirements?
- Requires macOS 14.0 or later. For the best experience, at least 16GB of memory is recommended on Apple Silicon Macs (M1, M2, etc.). If you have an Intel Mac or only 8GB of memory, you might want to consider BYOK (Bring Your Own Key) for better performance.
- Is there a free trial?
- We offer a 7-day free trial with full access to all features. No credit card required. Just download the app and start using it.
- What is your refund policy?
- We offer a 30-day no-questions-asked refund policy. If you're not satisfied for any reason, just email us within 30 days of purchase for a full refund.
- Is there an educational discount?
- Yes. We offer a 30% discount for students and educators. Simply enter your edu-issued email on this page and quickly get a discount.
- Do you offer regional pricing?
- Yes. We offer regional pricing based on purchasing power parity (PPP). Regional pricing eligibility is based on the country associated with your IP address.
- What does "lifetime license" mean?
- Your license includes all bug fixes, improvements, and new features. You get full access to the app forever, including all future updates.
- What happens if I register more devices than my license allows?
- You can view and deactivate your devices on the license page. If you've reached your device limit, deactivate a device you no longer use before activating a new one.
- Can I activate Refine offline?
- Yes. Refine supports Offline Activation. When you start activation in Refine, follow the in-app instructions: you'll need another device that can access the internet, such as a phone, to scan the QR code, confirm the device, download an Offline License File, then move that file back to your Mac and import it in Refine. An offline-activated device uses one device slot and cannot be deactivated for the first 30 days after activation. After that, you can release the slot from your license page.
- Who is behind Refine?
- I'm an indie developer focused on building small, useful tools that do one thing exceptionally well. I created Refine because I needed a grammar checker that respects privacy and works offline. You might also know my other app, Input Source Pro, which has helped thousands of multilingual users automatically switch input sources. Your support helps me continue improving these tools.
- When will a Windows or Linux version be available?
- Currently, I'm focused on making the macOS version as good as possible. Windows and Linux versions will take some time, and I don't have a timeline yet. If you're interested, you can join the waitlist to be notified when they become available.
Start Refining Your Writing
Download to improve every sentence you write
v1.35.1
macOS 14+
Full-featured 7-day free trial