Set OpenMark as Your Default Markdown Editor
Make OpenMark open automatically whenever you double-click a markdown file in Finder.
1Right-click a file in Finder
This is the quickest way to set OpenMark as the default for a specific file type. It works for any individual extension like .md or .markdown.
Find any .md file in Finder.
Right-click (or Control-click) the file and choose Get Info.
In the info window, find the Open with section. Click the dropdown and select OpenMark.
Click Change All… to apply this to every file with the same extension. Confirm when prompted.
Tip: You can also select a file and press ⌘I to open the info window.
2Use System Settings
macOS Tahoe lets you set default apps for file types directly in System Settings.
Open System Settings (Apple menu → System Settings).
Go to General → Default Apps.
Scroll down or search for the file extension you want to change (e.g. .md).
Select OpenMark from the list of available apps.
Supported file extensions
OpenMark can open any of these markdown file types. You may want to set it as the default for each one you use.
Troubleshooting
OpenMark doesn't appear in the “Open with” list
Make sure OpenMark is installed in your Applications folder (not still in Downloads). If you just installed it, try restarting Finder: hold ⌥ while right-clicking the Finder icon in the Dock and choose Relaunch.
Changes didn't apply to all files
The “Change All…” button only applies to files with the same extension. If you use both .md and .markdown files, you'll need to repeat the process for each extension.
Still having trouble? Contact support and I'll help you out.