Developers keep pasting JSON into online formatters and leaking secrets — so I built json-explorer

The problem

Debugging large or deeply nested JSON responses means pasting into online formatters (a privacy risk), squinting at jq output, or writing throwaway scripts — there is no instant zero-setup local tool that gives you a rich interactive view.

If you've hit this before, you know the friction — online formatters work but they upload your JSON to a third-party server. That's fine for public data; it's not fine for API responses containing auth tokens, PII, or internal service data.

As a solution, I created json-explorer

Visualize any JSON file as an interactive collapsible tree in your browser — with search, path tracking, and copy-to-clipboard

Zero dependencies. Run instantly:

npx json-explorer response.json

Output:

$ json-explorer response.json



json-explorer

  file:   /home/user/projects/api/response.json

  server: http://localhost:7777



Opening browser... press Enter to stop the server.

Your browser opens to a polished local dashboard. The server only listens on localhost — nothing leaves your machine.

Features

• Collapsible tree — top-level nodes open by default, deep nodes collapsed


• Live search — highlights matching keys and values, auto-expands parents


• Path display — hover any row to see its full dot/bracket path


• Copy to clipboard — copy any value or subtree as formatted JSON


• Expand all / collapse all buttons


• Auto-closes after 60 seconds (or press Enter)

How it works

Pure Node.js: reads the file, spins up an http.createServer on port 7777, serves a single self-contained HTML page with all CSS and JS inlined, then opens the default browser; server auto-closes after 60 seconds or on Enter.

Why I built it

Developers routinely paste JSON into online formatters like jsonformatter.org or jsoneditoronline.org, leaking API responses and auth tokens to third-party servers. jq is powerful but requires learning a mini-language for ad-hoc inspection. No popular zero-dep npx tool fills the gap — a local-web-dashboard format is the right choice here because the entire value is in the visual presentation, not the data transformation.

Try it

npx json-explorer --help

Part of µ micro — one new developer tool, shipped every day.