Kerlig AI vs RewriteBar

Kerlig AI is a macOS app that brings AI-powered writing assistance into any macOS app.

Summary

Kerlig AI and RewriteBar both bring AI-powered writing assistance into any macOS app, but they serve different workflows. Kerlig AI excels at deep, multimodal document interaction, broad model choice (350+ cloud and local), and a one-time license structure—ideal for heavy users and teams. RewriteBar offers a lightning-fast menu-bar UI with a polished command palette for grammar/style fixes, tone adjustments, summarization, expansion, translation (30 languages), and custom actions—available via subscription or one-time purchase. While RewriteBar is streamlined and cost-predictable, it lacks Kerlig's document/chat features and multi-model flexibility.

Core Features

What are the core features of Kerlig AI and RewriteBar?

Kerlig AIRewriteBar
Universal Integration
Works in any macOS app (Slack, Mail, VSCode, Figma, browsers, etc.)
Accessible in any app via a menu-bar command palette
Text Enhancements
Real-time grammar, spelling, tone, style, summarization & expansion
Real-time grammar, spelling, tone, style, summarization & expansion
Multimodal & Document Chat
Chat with PDFs, DOCX, EPUB, CSV, JSON, images, screenshots & web pages
Text-only; no built-in document or image ingestion
Translation
Unlimited languages via any connected LLM
Instant translation into 30 preset languages
Custom Actions & Presets
User-defined templates; powerful editor
User-defined templates; ultra-fast keyboard-driven actions
Model & API Flexibility
Supports 350+ LLMs
Supports 350+ LLMs

Platform & Compatibility

Kerlig AI

  • OS: macOS 10.15+ (Catalina and later)
  • Architecture: Intel & Apple Silicon
  • Works In: Any text field; Input Documents PDF, DOCX, EPUB, CSV, JSON, PNG, JPG, web pages

RewriteBar

  • OS: macOS 13+ (Ventura and later)
  • Architecture: Intel & Apple Silicon
  • Works In: Any application with a text field

Pricing & Licensing

Find the Right Plan For You

How does Kerlig AI compares with RewriteBar in terms of Pricing and License?

Kerlig AIRewriteBar
Free
Free
Start with 100 free Request
Entry
$47 for 1 Mac (one year updates)
$29 one-time
Multiple Devices
$67 for 2 Macs; $297 for 10 Macs
$5/month or $40/year
Refund & Trial
14-day money-back guarantee
Free trial available

Strengths & Gaps

Kerlig AI Strengths

  • Full multimodal support (images, OCR, redaction)
  • Custom AI Assistants + prompt library for task-specific workflows
  • Single, perpetual license with local security

Kerlig AI Gaps

  • No subscription tier (less flexible for light users)
  • Command menu less standardized
  • No built-in prompt-improvement tools

RewriteBar Strengths

  • Lightning-fast, keyboard-driven command palette
  • Smooth in-line text transformations (grammar, tone, summarize, translate)
  • Flexible subscription or one-time pricing

RewriteBar Gaps

  • Lacks document/chat or multimodal inputs
  • Focuses on text replacement and does not provide chat interface

Which to Choose?

Choose Kerlig AI if…

  • You need in-depth, multimodal interactions with documents and images.
  • You are willing to pay $47 for one year of updates.

Choose RewriteBar if…

  • You value a razor-sharp menu-bar command palette for rapid text edits.
  • You prefer a cheaper and simpler solution.
  • Your work is primarily text-based and you don't require document/chat features.

Pricing

Start using RewriteBar and get 20% off

Get 20% off for limited time! You can use code DISCOUNT20 at checkout to redeem your discount.

Trial

Try it for free

Free

  • Up to 100 requests
  • Access to our Cloud AI service
  • Includes 14 AI models
Start for free

No credit card required

Monthly Plan

Use our AI Cloud service (3 million words)

$5

USD

Monthly
  • Access our AI Cloud service (19 models)
  • Option to use your own AI provider API key
  • Choose from 11+ AI providers
  • Choose from 350+ AI models
  • Unlimited app updates
  • Use on unlimited devices

Billed monthly

Save 33%

Annual Plan

Use our AI Cloud service (3 million words)

$60

$40

USD

Annually
  • Access our AI Cloud service (19 models)
  • Option to use your own AI provider API key
  • Choose from 11+ AI providers
  • Choose from 350+ AI models
  • Unlimited requests (With API key)
  • Unlimited app updates
  • Use on unlimited devices

Billed annually

Use RewriteBar with an API Key

Requires an API key

Pay as you go

One-time purchase. Use your own API key — no subscription, no recurring fees.

$29

USD

OneTime

One time payment

  • Option to use your own AI provider API key
  • Choose from 11+ AI providers
  • Choose from 350+ AI models
  • Send request directly to AI provider
  • Option to use local models (e.g., Ollama)
  • Unlimited requests (With API key)
  • One-time payment
  • Licensed per device

FAQ

Frequently Asked Questions

Have a question? Contact me on Twitter or by email.

  • RewriteBar captures the currently selected text using the macOS clipboard and sends it to a language model for rewriting. The corrected version is then automatically pasted back, replacing the original text.

  • Yes. RewriteBar does not store or track any of your data. How your text is processed depends on the provider you choose:

    • RewriteBar (default): Your selected text is sent to the RewriteBar server, which forwards the request to a language model and returns the corrected version. We do not store your text or API key on our server.
    • Third-Party Providers (e.g. OpenAI, Mistral, Ollama): Your request is sent directly from your device to the provider’s API. RewriteBar never sees or processes your text.

    The app is built using native macOS tools and is just 6 MB in size — lightweight and privacy-focused.

  • Yes! RewriteBar works with almost any application or website that supports text input.

    Here are some examples:

    • Google Chrome
    • Google Docs
    • Microsoft Word
    • Slack
    • WhatsApp
    • Emails
    • Microsoft Teams
    • Notion
    • Visual Studio Code
  • Yes! You can try RewriteBar for free with up to 100 corrections. After that, you can upgrade to a subscription or one-time license.
  • Yes, you can request a refund within 7 days of purchase. Just reach out via email.
  • RewriteBar has been tested with English and German, but it should work with any language supported by ChatGPT. If you encounter issues with a specific language, feel free to contact us.

  • After your purchase, you'll receive an email with:

    • A download link for the app
    • A license key to activate it
    • The license key also includes unlimited app updates.

    The license key also includes unlimited app updates.

  • There are no additional costs with the subscription plan. If you're using the one-time license, you’ll need to provide an OpenAI API key, which may incur charges based on your usage. For most users, around $1 per month is enough to get started.
  • You can cancel your subscription through the Subscription Portal.
    If you have any questions, feel free to contact us via email.
  • No, a ChatGPT Plus subscription is not required. The OpenAI API operates on a pay-as-you-go basis, so you only pay for what you use. Alternatively, you can use the RewriteBar AI Cloud (included in the subscription plan).
  • The app requires macOS accessibility permissions to retrieve the selected text and replace it with the corrected version. This enables RewriteBar to work with any application. No data is stored.
  • You can create an account on OpenAI and generate a new API key.
    Setup instructions are available in our help center
  • The one-time license requires an Provider API key (OpenAI or other) and may incur usage-based costs from the Provider. The subscription plan includes access to the RewriteBar AI Cloud and is ideal for users who don’t want to manage their own API key.
  • No, there is no Windows version. RewriteBar is built with native macOS tools and isn’t compatible with Windows. If you're on Windows, you can try this alternative:Grammarsen.
  • You can reach out any time by email. I’m happy to help!