APILens — JSON, JWT & API inspector

Open-source, ad-free, local-first tools for inspecting API responses.

APILens auto-formats raw JSON/XML into a searchable, collapsible tree, decodes JWTs at a click, and copies any request as a cURL command. No account, no analytics, no ads.

Built as the clean, open-source alternative to the JSON-formatter extensions that went closed-source and started injecting ads.

Try it now (no install)

apilens-llau.onrender.com — the web app, free.

Paste JSON, XML, or a JWT and it formats instantly in your browser. Nothing is uploaded; everything runs client-side.

Features

Free (web + extension)

• Format & minify JSON/XML — auto-detects and renders a syntax-highlighted, collapsible tree with search.
• One-click JWT decode — any JWT expands into header, payload claims, and signature.
• Copy as cURL — export the current request as a ready-to-run curl command.
• Zero tracking — everything runs locally. No analytics, no telemetry.

Pro (web, $19 one-time lifetime)

• JSONPath query — extract exactly what you need ($.store.book[?(@.price < 10)].title).
• JSON diff — compare two documents and see every added / removed / changed path.
• Large-file mode — raise the cap from 20k nodes / 2 MB to 200k nodes / 20 MB.
• Lifetime license — one purchase, delivered instantly, no subscription.

Install (extension, manual developer load)

1. Clone this repo, or download dist/apilens-v0.1.0.zip and unzip it.
2. Open chrome://extensions, enable Developer mode.
3. Click Load unpacked and select the extension/ folder.

A Chrome Web Store listing is not yet published; the web app (above) needs no install.

Why open source?

The most-installed JSON formatter (2M+ users, 4.5★) went closed-source in 2025 and began injecting ads. APILens is the opposite: MIT-licensed, readable, and local-first. If we add a feature you don't like, fork it.

Privacy

• No analytics, no tracking, no external telemetry.
• Inspected responses are rendered in-page and never uploaded anywhere.
• Source is fully open so you can verify both claims.

Repo layout

• web/ — the web app (static frontend + stdlib-only Python backend with Stripe license delivery).
• extension/ — the MV3 Chrome extension.
• scripts/ — tests and deploy tooling.

License

MIT. Built by Meridian Digital.

Project status

v0.2.0 — web app live and monetized (free + $19 lifetime Pro). Extension shipped open-source.