Your offline AI for perfect grammar
Seamless AI writing assistance across your favorite apps. Private, lightning-fast, and customizable.
v1.16
macOS 14+
Full-featured 7-day free trial
Privacy first, always
Writing That Never Leaves Your Mac
Unlike cloud-based tools, Refine processes everything locally using advanced AI models.
Every 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.
Plays Nice with Your Favorite Apps
No setup needed. Just start writing and get instant grammar suggestions.
And many more applications across macOS
Works in Your Language
Check grammar in 50+ languages including regional dialects
English
German
French
Spanish
Portuguese
Chinese
Also supports: Arabic · Czech · Danish · Dutch · Finnish · Greek · Hebrew · Hindi · Hungarian · Indonesian · Italian · Japanese · Korean · Norwegian · Polish · Romanian · Russian · Swedish · Thai · Turkish · Ukrainian · Vietnamese
Flexible Checking Modes
Choose between automatic real-time checking or manual control with keyboard shortcuts
Automatic Checking
Get real-time grammar suggestions as you type. Perfect for continuous writing flow without breaking your concentration.
Instant feedback
See corrections as you type
No interruption
Suggestions appear inline
Always on
Works in every text field
Manual Control
Check grammar on demand with customizable shortcuts. Perfect for focused writing and multilingual content.
Custom Prompt
Personalized Writing
Customize to Your Style
Create custom prompts that match your unique voice and writing needs. Save unlimited prompts and switch between them instantly.
- Professional Email
- Polish business communications with formal tone and clarity
- Academic Writing
- Enhance scholarly papers with precision and rigor
- Creative Writing
- Refine stories while preserving your unique voice
- Technical Documentation
- Make technical content clear and accessible
- Social Media
- Craft engaging posts that capture attention
- Personal Style
- Create custom prompts for your unique needs
Advanced AI Options
Want More Power?
Just Bring Your Own Key
While our local model handles most tasks brilliantly, you can connect your own API keys for access to the most advanced AI models
Use Your Own API Key
Connect directly to OpenAI, Anthropic, or Google – no proxy, no middleman, just you and the provider
Access Powerful Models
Use ChatGPT, Claude, Gemini and other cutting-edge language models
Keys Stay with You
API keys are stored securely in your system keychain. Your data never touches our servers
Seamless Integration
Switch between local and cloud models with a single click
Simple, honest pricing
Own it forever. No subscriptions, no hidden fees.
One-Time License
Buy once, get all updates within the major version. We're working hard every day to make this app better, and your support helps fuel continuous improvements.
What's included
- AI-powered writing refinement
- Lightning-fast local processing
- Works offline anywhere
- All updates within major version
- 3 devices per license
- Priority support & feedback
Pay once, own it forever
$30USD
Try it before you buy! Download the free trial version to see if it fits your needs.
What's New
Constantly Improving
We're shipping improvements frequently to make Refine even better
Version 1.16
Released 2 mins ago
Improvements
- Improved app stability and performance
- Reduced memory usage when using cloud model
- Updated UI/UX of App Filter to avoid misleading interface
Bug Fixes
- Fixed a potential crash issue introduced in version 1.13
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 happens locally using offline large language models (LLMs) that run directly on your machine.
- What apps does it work with?
- Works with most macOS apps including Mail, Messages, Safari, Chrome, Pages, Word, Slack, Notion, and many more.
- 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.
- Is there an educational discount?
- Yes! We offer a 30% discount for students and educators. Just send us an email from your current student, teacher, or institutional email address.
- What does "lifetime license" mean?
- Your license includes all bug fixes, improvements, and new features within v1.x forever. We're fully focused on making v1 amazing and have no plans for a v2. If a new major version ever happens, perhaps many years from now, it would only be for truly groundbreaking changes. Even then, existing customers would receive upgrade pricing, and v1.x would continue to work indefinitely.
- 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. I believe in keeping apps focused and lightweight instead of cramming in endless features. My goal is simple: to create tools that solve specific problems elegantly, respect your privacy, and just work. With your support, I can keep making these tools even better.
- Why do you use "we" if it's just you?
- It's a habit from writing documentation and support emails, where "we" sometimes just sounds more natural than constantly saying "I". But yes, it's just me, a solo developer working on Refine.
- How quickly will I get a response to my email?
- I usually reply within one day. I read every email and will get back to you as soon as possible.
Refine Your Writing
Download to improve every sentence you write
v1.16
macOS 14+
Full-featured 7-day free trial