Best JSON Tools

Pretty-print messy or minified JSON with adjustable indent (2 / 4 spaces or tabs) and an optional 'sort keys alphabetically' mode. Copy or download the result, all in your browser.

Validate JSON against the RFC 8259 spec and see exactly where errors occur — line, column and a human-readable explanation — instead of the generic 'Unexpected token' message you'd get from a native parser.

Remove indentation and whitespace from JSON to produce a single-line compact payload. See the exact byte savings and copy / download the result instantly.

Visualize any JSON document as a virtualized, collapsible tree with type-based color coding, search, expandable paths, and copy-on-click. Stays responsive for very large payloads.

Diff two JSON documents and highlight exactly which keys were added, removed, or changed — side-by-side or in a unified inline view. Structural only, so re-ordered keys are not flagged.

Convert JSON into equivalent YAML 1.2 syntax for Kubernetes manifests, Docker Compose, or any config that prefers YAML. Configurable indent and flow style; runs entirely in your browser.

Paste any JSON object or array and get ready-to-use TypeScript interfaces/types. Recursive type inference with deduplication, PascalCase or camelCase naming, and interface/type alias toggle.

Generate valid JSON Schema (draft 2020-12 / 2019-09 / draft-07) from your JSON data. Infers types, detects string formats, and identifies optional vs required fields across multiple samples.

Check whether a JSON document conforms to a JSON Schema (draft-07 / 2019-09 / 2020-12) and see exactly which rules failed, with JSON Pointer paths for each violation.

Compare two JSON documents and produce a standards-compliant JSON Patch (add/remove/replace operations). Built on the same structural diff engine as JSON Diff.

Combine 2+ JSON documents using a recursive deep-merge with three array strategies (replace, concatenate, merge-by-index). Label your sources and see which keys conflicted.

Test JSONPath expressions in real-time against sample JSON. Shows match count and results. Uses jsonpath-plus for standards-compliant JSONPath syntax.

Produce arrays of realistic mock JSON objects — names, emails, addresses, prices, UUIDs, and more — based on a customizable field template. Seeded random for reproducible output.

Flatten deeply nested JSON objects into dot-notation key-value pairs, or unflatten them back. Configurable delimiter and array handling.

Search keys and values in any JSON document with case-sensitive/insensitive toggle. Finds matches in keys, string values, numbers, booleans, and nulls.

Extract all unique key paths from a JSON document, or pull all values for a specific key across an array of objects. Two modes with copy support.

Sort every object's keys in a JSON document — ascending (A→Z) or descending (Z→A). Uses your existing JSON parser for error feedback.

Escape a raw string for embedding in JSON (e.g. newlines become \n), or unescape an escaped JSON string back to plain text.

Scan JSON text for duplicate keys — which are syntactically valid but often indicate a copy-paste or merge error. Unlike JSON.parse (which keeps the last value), we flag every duplicate.

Parse YAML text and produce equivalent JSON using the js-yaml library. Works with any valid YAML 1.2 document.

Transform JSON documents into well-formed XML. Arrays become repeated elements; nested objects become nested elements.

Convert well-formed XML into equivalent JSON objects. Repeated child elements become arrays; attributes are prefixed with @.

Analyze which keys and branches contribute the most bytes to your JSON. Each path shows absolute size, percentage, and a proportional bar.

Convert a JSON array of objects into SQL table definitions and INSERT statements. Type inference, table naming, and optional DROP TABLE prefix.

Turn a JSON array of objects into a ready-to-use Markdown table for docs, READMEs, and wikis. Headers from keys, pipes in the right places.

Analyze arrays of objects and get per-field stats: min, max, avg, unique count, null count, top values, and type inference.

Detect and report circular references in JSON data that would cause JSON.stringify to throw a TypeError.

Transform an array of objects into a key-indexed object (like Lodash keyBy) or go the other direction — object back to array.

Remove // and /* */ comments plus trailing commas from JSONC/JSON5 files to produce strict RFC 8259 JSON.

Paste or drop a CSV and instantly get structured JSON. Smart numeric coercion, pretty-print, and copy/download.

Convert any JSON array of objects into a clean CSV. Flattens nested keys with dotted notation, escapes commas/quotes per RFC 4180, and offers a customizable delimiter + UTF-8 BOM toggle for Excel compatibility.