JSON Formatter Pro - Validate, Query & Diff

Format, validate, query & diff JSON. Pretty-print with syntax colors, JSONPath, schema validation, and saved history.

Stop fighting with messy JSON. Format, validate, query, and compare API responses in a single click — without ever uploading a byte. 🚀 🚀 WHY DEVELOPERS LOVE JSON FORMATTER PRO JSON is everywhere: REST APIs, GraphQL responses, config files, log streams, webhook payloads, NDJSON exports. And in every one of those places, you eventually hit JSON that's been minified, mangled, or badly indented. JSON Formatter Pro turns that mess into a clean, color-coded, navigable tree in milliseconds, with the power tools senior engineers actually use day to day: JSONPath, JSON Schema validation, diff, history, and exports. It's fast. It's offline-first. It's privacy-respecting (your data never leaves your browser). And it stays out of your way until you click the icon. ⚡ EVERYTHING IN THE FREE PLAN ✓ Pretty-print with 2-space, 4-space, or tab indents ✓ Minify to a single compact line for clipboard or curl ✓ Validate with precise line-and-column error pointers ✓ Collapsible tree view with syntax colors for keys, strings, numbers, booleans, and null ✓ Copy formatted JSON to clipboard with one click ✓ Download formatted output as a properly named .json file ✓ Recent history of the last 5 payloads ✓ Twenty formats per day, no signup, no email required 🔓 WHAT PRO UNLOCKS ✦ JSONPath queries — extract exactly the values you need from deeply nested payloads. Supports root selectors, dotted properties, array indices, unions, slices, wildcards, and recursive descent. ✦ JSON Schema validation — paste a draft-07 schema and instantly see which fields fail. Type, properties, required, enum, const, length and range constraints, oneOf, anyOf, allOf — all supported with clear error paths. ✦ Side-by-side diff — drop two JSON payloads side by side and see exactly what's added, removed, and changed. Dotted paths point to the exact field; value differences are highlighted. ✦ Saved history — last 50 payloads kept locally. Find that response from yesterday in one click. ✦ Export to CSV / YAML / TOML — convert API responses into spreadsheet-ready CSV, friendlier YAML, or TOML for config files. ✦ Unlimited daily formats — for the engineers who format hundreds of payloads a day. 🎯 WHO IT IS FOR Backend developers debugging API responses. Frontend developers inspecting network-tab JSON. QA engineers verifying contract compliance. Data analysts cleaning up exports. DevOps engineers checking config files. Technical writers formatting examples for docs. Anyone who has ever opened a 12,000-character single-line JSON blob and wished it would just be readable. 🛠️ HOW IT WORKS 1️⃣ Pin the extension to your toolbar (one-time setup). 2️⃣ Click the icon to open the popup. 3️⃣ Paste your JSON, or click "Load from tab" if you are already viewing a JSON response. 4️⃣ Click Format. The tree view appears instantly with syntax colors and collapsible nodes. 5️⃣ Use Pro tools to query, validate, diff, or export. 💡 REAL USE CASES → Inspect a 5MB Stripe webhook payload without freezing your browser → Pull every email address from an array of users with $.users[*].email → Validate that a config file has all required keys before shipping it → Diff staging vs production responses to find that one drifted field → Convert an API response to CSV and paste it into a spreadsheet → Reformat a minified payload from a log line into something readable 🔒 PRIVACY YOU CAN VERIFY Your JSON never leaves your browser. All formatting, validation, querying, schema checks, and diffs happen 100% locally in your popup. No servers, no upload, no logging. The only network traffic the extension makes is a license check (sending only a random device ID) and anonymous funnel counts. No content. No tracking pixels. No third-party analytics. 📊 PERFORMANCE & BENCHMARKS Formatting a 1MB payload takes under 50ms on a typical laptop. 5MB takes under 250ms. The tree view lazy-renders nodes so deep nesting stays smooth. Whole bundle ships at ~80KB gzipped, so Chrome stays light. 🆚 WHY THIS OVER THE ALTERNATIVES ✓ Unlike online JSON formatters, your data never gets uploaded — everything runs locally ✓ Unlike VSCode extensions, you don't need to leave your browser ✓ Unlike Postman, it stays small and never makes API calls — pure formatter focus ✓ Unlike jq, no terminal and no syntax to memorize — clickable GUI 🛡️ SECURITY Manifest v3. Zero remote code. No external CDN dependencies. Every release is audited by the lint-remote-code tool before submission. All processing logic ships inside the bundle. ❓ FREQUENTLY ASKED QUESTIONS Q: Does it work offline? A: Yes. Every Free feature works without a network connection. Pro license verification needs network the first time, then caches for 24 hours. Q: How big a payload can it handle? A: Tested cleanly up to 5 MB. Native JSON parsing scales with your machine's memory. Q: Is my data sent anywhere? A: No. JSON parsing happens entirely in your browser. Q: What is the difference between Monthly ($2.99) and Lifetime ($9.99)? A: Same Pro features, different commitment. Lifetime pays for itself in four months. Q: Can I get a refund? A: Within 30 days of purchase, yes. Email support and we will refund, no questions. 🚀 GET STARTED Install the extension, pin it to your toolbar, paste your first JSON payload, and never go back to "Notepad with find-and-replace" again. JSON Formatter Pro is the JSON tool every developer eventually wishes they had installed sooner. Start today, and you will be recommending it to your team by tomorrow.