Splat

Splat shows your Markdown source with syntax colours on one side and a live preview on the other, and you can type in either. Edits made in the preview become minimal changes to the source, so lines you did not touch stay byte-for-byte the same and Git diffs stay clean. It reads CommonMark and GitHub Flavored Markdown, Obsidian links and callouts, Pandoc and Typora extensions, and renders LaTeX formulas and Mermaid, Graphviz and PlantUML diagrams offline. Documents export to PDF, HTML or Word.

It requires macOS 14 or later, on Apple silicon or Intel; the disk image is a universal build, signed with a Developer ID certificate and notarized by Apple. The app has no telemetry and makes no network requests by default. It checks for updates only after you agree to it or choose Check for Updates, and then it only names the app and its version. Web images load only after you give permission. The README lists some limits, such as embedded HTML and front matter being read-only in the preview, and it is tested less on Intel. The project is dual-licensed under Apache-2.0 or MIT.