JSON Viewer

JSON Viewer is a clean, offline developer tool that turns raw JSON into a collapsible tree you can actually read. Paste a payload, format it, validate it, and walk through it node by node — no login, no upload, no clutter.

Whether you are debugging an API response, inspecting a config file, or cleaning up a messy log dump, JSON Viewer gives you the parser, formatter, and tree explorer in one focused screen.

KEY FEATURES

• Tree view with collapse and expand at every level

• Syntax highlighting (keys blue, strings green, numbers orange, null and booleans red)

• Prettify with 2 or 4 space indent

• Minify to a single compact line

• Validate JSON with clear, line-aware error messages

• Paste from clipboard and copy results with one tap

• Adjustable font size from 10 to 24 pt

• Dark mode plus automatic system theme follow

• 37 languages with full RTL support for Arabic

• Works offline, no account

WHO IT IS FOR

• Backend, frontend and full-stack developers

• Mobile engineers working with Android, iOS, Flutter, or React Native

• API integrators debugging REST and GraphQL responses

• Data analysts cleaning JSON exports and datasets

• DevOps and SRE engineers reading configs and structured logs

WHY THIS ONE

Privacy first. Every byte of JSON you paste stays on your device. Nothing is uploaded to a server, nothing is shared, nothing is logged.

No bloat. This is not a 50 MB IDE pretending to be a viewer. It launches fast, does JSON well, and stays out of your way.

Truly multilingual. The interface ships in 37 hand-localized languages, not machine-translated fragments, so the tool feels native wherever you work.

Supported by a single small banner ad to keep development sustainable. No paywall, no subscription, no upsell popups.

TYPICAL USE CASES

• Inspecting Stripe and PayPal webhook payloads

• Reading Firebase Remote Config and Firestore exports

• Debugging GraphQL and REST API responses

• Formatting messy server log JSON into something readable

• Reading package.json, tsconfig.json, and other project configs

Works with JSON from APIs, config files, package.json, tsconfig, Firebase, Stripe, GitHub, and any REST or GraphQL endpoint.

Install JSON Viewer and keep a proper JSON formatter, validator and tree explorer in your pocket.