TinyJSON

A native macOS JSON editor. Collapsible tree on one side, syntax-highlighted source on the other. Tells you exactly where it's broken.

Features

• Three-panel layout — file sidebar, editor, and tree preview
• Syntax highlighting — keys, strings, numbers, booleans, nulls
• Live preview — collapsible tree view rendered as you type
• Directory browsing — navigate folders, subdirectories, and files
• Quick open — fuzzy file finder (Cmd+P)
• Auto-save — saves as you type with dirty-file indicators
• Find & replace — native macOS find bar (Cmd+F)
• JSON validation — real-time error reporting with line numbers
• Tab support — multiple files in tabs
• Line numbers — optional gutter with current line highlight
• Word wrap — toggle with Opt+Z
• Font size control — Cmd+/Cmd- to adjust, Cmd+0 to reset
• Light & dark mode — follows system appearance
• Status bar — line count, file size, validation status
• Open from Finder — double-click .json or .geojson files to open in TinyJSON
• On-device AI — Cmd+K to ask questions about your data (CoreML, fully offline)

Requirements

• macOS 26.0+
• Xcode 26+ (to build)

Build

xcodegen generate --spec project.yml

xcodebuild clean build \
  -project TinyJSON.xcodeproj \
  -scheme TinyJSON \
  -configuration Release \
  -derivedDataPath /tmp/tinybuild/tinyjson \
  CODE_SIGN_IDENTITY="-"

rm -rf /Applications/TinyJSON.app
cp -R /tmp/tinybuild/tinyjson/Build/Products/Release/TinyJSON.app /Applications/
xattr -cr /Applications/TinyJSON.app

Keyboard Shortcuts

Shortcut	Action
Cmd+N	New file
Cmd+O	Open folder
Cmd+S	Save
Cmd+P	Quick open
Cmd+F	Find
Cmd+K	AI assistant
Opt+Z	Toggle word wrap
Opt+P	Toggle preview
Opt+L	Toggle line numbers
Cmd+= / Cmd+-	Font size
Cmd+0	Reset font size

Tech

Built with SwiftUI, NSTextView, and TinyKit.

Part of TinySuite

Native macOS micro-tools that each do one thing well.

App	What it does
TinyMark	Markdown editor with live preview
TinyTask	Plain-text task manager
TinyJSON	JSON viewer with collapsible tree
TinyCSV	Lightweight CSV/TSV table viewer
TinyPDF	PDF text extractor with OCR
TinyLog	Log viewer with level filtering
TinySQL	Native PostgreSQL browser

License

MIT