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 • 100% offline, no account, no tracking, no analytics 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.