QLook JSON

QLook JSON is a Quick Look extension that shows you JSON files right in Finder — just press the space bar. With no need to open a separate app or drag files into another tool, it brings color syntax highlighting and clean formatting to macOS’s built-in preview.

It supports .json, .jsonc (JSON with comments), and .jsonl / .ndjson (line-delimited JSON), and lets you switch instantly between three views with tabs.

• Original — shows the source as-is, with syntax highlighting and line numbers
• Pretty — a neatly indented view that preserves key order and JSONC comments, with collapsible nested sections
• YAML — converts the same data into an easy-to-read YAML block format

Key features

• Fast preview — check instantly with a single space bar press in Finder
• Native performance — written in pure native code with no heavy web view, so it’s light, fast, and scrolls smoothly even through large files
• Syntax highlighting — clearly distinguishes keys, strings, numbers, booleans, and null
• Dark Mode ready — automatically switches its palette to match the system appearance
• Line numbers — for JSONL, shows both source and formatted line numbers
• Copy with one click — copy the content of the tab you’re viewing to the clipboard with a single button. Take the pretty-formatted JSON or converted YAML and use it right away
• Universal binary — runs natively on both Apple Silicon and Intel Macs

Privacy

All processing happens entirely on your Mac. No network communication, no transmission to external servers, no embedded web view. It runs inside the App Sandbox and accesses only the file you opened for preview. Your data never leaves your device.

Beyond preview, a converter

Without opening a separate tool, you can neatly format (Pretty) JSON or convert it to YAML right from the preview, then grab it instantly with the copy button. It’s especially handy when you need to tidy up JSON crammed onto one line, or quickly turn JSON into YAML.

For preview responsiveness, large files are safely displayed up to 5 MB.