OnyxNote: Text & Code Editor
Markdown & Syntax Highlighting
Only for Mac
Free
Mac
A native Mac workspace for plain text, Markdown and code. Switch tabs, highlight syntax, and find and replace with familiar macOS tools.
OnyxNote is a native text and code editor for Mac. Write plain text notes, edit Markdown, and work on scripts and source files in a clean workspace that follows your system appearance.
A CLEARER VIEW OF YOUR CODE
Syntax highlighting helps you read Swift, Python, JavaScript, HTML, CSS, JSON and Markdown. Choose a language mode for each file, show line numbers, and adjust the font size and word wrapping to suit your work.
KEEP YOUR FILES CLOSE
Open several documents in tabs and use the sidebar to switch between them. Each document keeps its own undo history, selection and scroll position. Open separate windows when you want more room for your work.
FAMILIAR MAC TOOLS
Use the built-in macOS Find and Replace controls and familiar keyboard shortcuts to create, open, search and save files. A native toolbar and automatic light and dark appearance keep the interface at home on your Mac.
WORK WITH YOUR OWN FILES
Open and save local text files, including UTF-8 and UTF-16 documents. OnyxNote preserves line endings, prompts you about unsaved changes when closing, and checks for external file changes before overwriting a saved document.
FOR EVERYDAY EDITING
Draft a note, update a README, adjust a JSON configuration, or make a quick change to a script. Work offline without creating an account.
OnyxNote focuses on editing text and source files. Markdown is edited as source text; code execution and rendered Markdown previews are not included. Save your work using Save or Save All.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
A refreshed native Mac workspace and more dependable everyday editing.
• Updated toolbar and sidebar with automatic light and dark appearance.
• Improved tabs and multiple windows, with independent undo history and preserved selection and scroll position.
• Native Find and Replace, adjustable font size, word wrapping and line numbers.
• Improved UTF-8 and UTF-16 handling and preservation of line endings.
• Better handling of cancelled or failed saves, unsaved changes and files modified outside OnyxNote.
• Fixed visual glitches around the editor and line-number ruler.
The developer, ARTCOAST LLC, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- ARTCOAST LLC
- Size
- 2 MB
- Category
- Developer Tools
- Compatibility
Requires macOS 26.0 or later.
- Mac
Requires macOS 26.0 or later.
- Mac
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 Artcoast LLC