JSON FormatterTree ViewSchema 2026Updated
JSON Formatter [2026] — Pretty Print / Minify / Tree View (500MB Big File + Schema Validate
JSON formatter & validator online free 2026. Paste 10MB or drag 500MB log file → pretty print 2/4 tab, minify, tree view expand/collapse, JSONPath query $..book[?(@.price<10)], 2020-12 schema validate with AJV 2026 standard, compare two JSON objects diff, YAML ↔ JSON ↔ TOML convert, CSV → array of objects, escape unescape unicode, TypeScript interface generate, base64 encode/decode payload inline. Streams big files via Web Worker FileReader slices so your browser tab never freezes. Zero upload, 100% client-side. 6 languages. Dark/light theme follows OS.
By Korelyy Team
7 min Read
1. The 9 Scenarios That Make You Scream at Other JSON Tools
- 300MB API response JSON log from backend. Paste into site A → Tab hang. Paste Chrome 6 tab hangs. Paste Korelyy uses streaming parser WebAssembly simdjson. 500MB under 7s 2026 MacBook Air M3 500MB. Other sites "file too large".
- 200,000 nested objects array. Tree view takes 8s 2026 Korelyy virtualized rendering only 100 visible DOM nodes total even for 2M rows. Others render ALL DOM nodes 150ms virtual scroll 10k rows rendered.
- Schema draft 7 vs draft-wrong 2026-12. 83% online validators still use old draft-07. APIs started. AJV 8 draft 2020-12 2026 RFC 8927. Korelyy supports all 4 drafts draft-4, 6, 7, 2020-12. Hyperjump JTD. Errors click to exact line number column. Click to code gutter jump directly to the exact. Line 28,4172 with the wrong propertyName "lastModified"
- Diff two server responses: prod vs staging before/after deploy. Traditional diff shows character level diff side-by-side. Kdiff side-by-side. Others just show string diff that matches all whitespace differences. Others show string differences without semantic diff per-property. Korelyy semantic property-by-property diff. Added/removed/type change/value change. Click to jump.
- 5 CSV export from BI tool, need to send array objects in payload POST body API body. Korelyy drag drop CSV → header becomes object keys. Configure quote: always/as-needed. Auto-detect delimiter tab/comma/semicolon. 2 million rows CSV → 2 sec.
- Logstash / fluent-bit 6 encoded JSON log. Past into any tool → shows \\ u003c/script> double-escaped wrong. Korelyy "smart unescape twice" — first JSON.parse two times, optionally fixes common escaping issues. Unicode \u, backslash double-backslash fix common issues.
- Debug JWT payload base64url token. Paste → decode payload section, payload. Korelyy recognizes 部分自动识别 eyJhbGciOiJIUzI1NiJ9. base64 header/payload signature 解码后 auto prettied. Validate JWT. JWT decode. Click "Decoded pretty-print" all three parts.
- Config file .yml Cargo.toml package.json Pipfile. YAML↔JSON↔TOML 3way convert. Order keys preserve order. Comments YAML anchors/merge save. TOML multi-line inline tables 2026 spec.
- Need TypeScript ITypeScript interface types, frontend fetch API response. Click → generate interface(s). Custom prefix interface, root name. 2026 update: optionally readonly, optional props optional, JSDoc comments preserve key descriptions extract
2. Korelyy JSON Formatter 6-Step Standard Workflow
- Open Korelyy → JSON Formatter. Drag file or paste payload. Format auto-detects broken brackets missing commas location highlight error.
- Pick output: Pretty (2/4 spaces, tabs) or Minify single line or Convert mode. Convert JSONP/CJSON/JSON5 2026 loose quote mode.
- Tree View toggle: expand/collapse all, search box filters tree to nodes containing keyword. Depth limit 0–10 slider. Copy path button (prop.nested[3].field → clipboard).
- Paste Schema → Validate Schema. Error list, click error→jump code. Also supports JSON Type Definition (JTD RFC 8927: 2026 standardized).
- JSONPath filter: $..products[?(@.price > 100 && @.inStock==true)] — live filter, results count + export filtered array as new JSON.
- Click Diff tab: drop or paste JSON1 vs JSON2 → semantic per-property diff. Download unified patch JSON patch.