Your offline AI for perfect grammar

Seamless AI writing assistance across your favorite apps. Private, lightning-fast, and customizable.

Download for Mac

v1.21

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.

Refine works with Apple Messages app for grammar checking
Messages
Refine works with Apple Mail app for email grammar checking
Mail
Refine works with Safari browser for web writing
Safari
Refine works with Google Chrome browser
Chrome
Refine works with Apple Pages for document editing
Pages
Refine works with Microsoft Word for professional documents
Word
Refine works with Slack for team communication
Slack
Refine works with Notion for note-taking and documentation
Notion
Refine works with Apple Notes app
Notes
Refine works with Bear writing app
Bear
Refine works with Ulysses writing app
Ulysses
Refine works with Discord for chat messages
Discord

And many more applications across macOS

Never lose your flow

Stuck on a Word? Just Write It in Your Language

When you can't think of the right word or phrase, simply write it in your native language. Refine will suggest the perfect translation without interrupting your writing flow.

Inline Suggestions.

Get natural phrasing right where you type, without breaking your sentence.

Context-Aware Suggestions.

Understands the surrounding context to suggest the most natural translation for each word.

Uninterrupted Flow.

Keep writing without stopping to look up words. Just use your native language and continue.

Works in Your Language

Check grammar in 50+ languages, including regional dialects.

English

🇺🇸American English
🇬🇧British English
🇨🇦Canadian English
🇦🇺Australian English
🇮🇳Indian English
+4 more

German

🇩🇪German
🇨🇭Swiss German
🇦🇹Austrian German

French

🇫🇷French
🇨🇦Canadian French
🇨🇭Swiss French
🇧🇪Belgian French

Spanish

🇪🇸Spanish
🇲🇽Mexican Spanish
🇦🇷Argentine Spanish
🇨🇴Colombian Spanish
🇨🇱Chilean Spanish

Portuguese

🇵🇹Portuguese
🇧🇷Brazilian Portuguese

Chinese

🇨🇳Simplified Chinese
🇹🇼Traditional Chinese
🇭🇰Cantonese

Also supports: Arabic · Bosnian · Croatian · Czech · Danish · Dutch · Finnish · Greek · Hebrew · Hindi · Hungarian · Indonesian · Italian · Japanese · Korean · Norwegian · Polish · Romanian · Russian · Serbian · Slovak · 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.

Check in English (British)
E
Toggle "Check Writing Automatically"
Z
Check Selected Text in Floating Editor
F

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.

Early bird pricing - future versions will cost more as features expand

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

$59$36USD

Save 39% off the regular price

Purchase a License

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 1.21

Released 1 week ago

Bug Fixes

  • Fixed an issue where the model might not launch when opening the app

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 7-day no-questions-asked refund policy. If you're not satisfied for any reason, just email us within 7 days of purchase for a full refund.
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.
What happens if I register more than 3 devices?
Your license allows activation on up to 3 devices. If you try to register a 4th device, the oldest device will automatically be deactivated to make room for the new one.
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.
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.
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.
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.

Start Refining Your Writing

Download to improve every sentence you write

Download for Mac

v1.21

macOS 14+

Full-featured 7-day free trial