JSON Tools
JSON is the most common data interchange format on the web. These tools help you format, validate, convert, and analyze JSON without leaving the browser — from pretty-printing a minified API response to measuring exactly which keys are bloating your payload.
Most popular
- jsonJSON Formatter● ready
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.
- jsonJSON Validator● ready
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.
- jsonSize Analyzer● ready
Measure your JSON's byte size and see which keys are bloating it. This free JSON size calculator breaks down every path's contribution with absolute size, percentage, and a visual bar — all in your browser.
- jsonJSONPath● ready
Test JSONPath expressions in real-time against sample JSON. Shows match count and results. Uses jsonpath-plus for standards-compliant JSONPath syntax.
- jsonJSON Tree Viewer● ready
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.
Format & Validate
- jsonJSON Formatter● ready
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.
- jsonJSON Validator● ready
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.
- jsonJSON Minifier● ready
Remove indentation and whitespace from JSON to produce a single-line compact payload. See the exact byte savings and copy / download the result instantly.
- jsonJSON Tree Viewer● ready
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.
- jsonJSON Diff● ready
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.
- jsonSearch● ready
Search keys and values in any JSON document with case-sensitive/insensitive toggle. Finds matches in keys, string values, numbers, booleans, and nulls.
Convert
- jsonJSON → CSV● ready
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.
- jsonJSON → YAML● ready
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.
- jsonYAML → JSON● ready
Parse YAML text and produce equivalent JSON using the js-yaml library. Works with any valid YAML 1.2 document.
- jsonJSON → XML● ready
Transform JSON documents into well-formed XML. Arrays become repeated elements; nested objects become nested elements.
- jsonXML → JSON● ready
Convert well-formed XML into equivalent JSON objects. Repeated child elements become arrays; attributes are prefixed with @.
- jsonJSON → TS● ready
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.
- jsonJSON → SQL● ready
Convert a JSON array of objects into SQL table definitions and INSERT statements. Type inference, table naming, and optional DROP TABLE prefix.
- jsonJSON → MD Table● ready
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.
- jsonJSONC → JSON● ready
Remove // and /* */ comments plus trailing commas from JSONC/JSON5 files to produce strict RFC 8259 JSON.
Analyze & Transform
- jsonSize Analyzer● ready
Measure your JSON's byte size and see which keys are bloating it. This free JSON size calculator breaks down every path's contribution with absolute size, percentage, and a visual bar — all in your browser.
- jsonJSONPath● ready
Test JSONPath expressions in real-time against sample JSON. Shows match count and results. Uses jsonpath-plus for standards-compliant JSONPath syntax.
- jsonFlatten● ready
Flatten deeply nested JSON objects into dot-notation key-value pairs, or unflatten them back. Configurable delimiter and array handling.
- jsonSort Keys● ready
Sort every object's keys in a JSON document — ascending (A→Z) or descending (Z→A). Uses your existing JSON parser for error feedback.
- jsonKey Extractor● ready
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.
- jsonDup Keys● ready
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.
- jsonArray Stats● ready
Analyze arrays of objects and get per-field stats: min, max, avg, unique count, null count, top values, and type inference.
- jsonCircular Ref● ready
Detect and report circular references in JSON data that would cause JSON.stringify to throw a TypeError.
- jsonArray → Object● ready
Transform an array of objects into a key-indexed object (like Lodash keyBy) or go the other direction — object back to array.
- jsonJSON Line Numbers● ready
A lightweight JSON viewer with a synchronized line-number gutter. Paste JSON and see every line numbered.
Schema & Generate
- jsonSchema Gen● ready
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.
- jsonSchema Validator● ready
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.
- jsonJSON Patch● ready
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.
- jsonJSON Merge● ready
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.
- jsonMock Data● ready
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.
- jsonEscape● ready
Escape a raw string for embedding in JSON (e.g. newlines become \n), or unescape an escaped JSON string back to plain text.
- jsonJSON → GraphQL● ready
Paste a JSON object and get a GraphQL schema with inferred types — nullable or required.
- jsonJSON for Chat● ready
Generate chat-ready JSON snippets — auto-split into multiple messages to fit platform character limits.
All tools
- jsonJSON → CSV● ready
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.
- jsonJSON Formatter● ready
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.
- jsonJSON Validator● ready
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.
- jsonJSON Minifier● ready
Remove indentation and whitespace from JSON to produce a single-line compact payload. See the exact byte savings and copy / download the result instantly.
- jsonJSON Tree Viewer● ready
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.
- jsonJSON Diff● ready
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.
- jsonJSON → YAML● ready
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.
- jsonJSON → TS● ready
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.
- jsonSchema Gen● ready
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.
- jsonSchema Validator● ready
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.
- jsonJSON Patch● ready
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.
- jsonJSON Merge● ready
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.
- jsonJSONPath● ready
Test JSONPath expressions in real-time against sample JSON. Shows match count and results. Uses jsonpath-plus for standards-compliant JSONPath syntax.
- jsonMock Data● ready
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.
- jsonFlatten● ready
Flatten deeply nested JSON objects into dot-notation key-value pairs, or unflatten them back. Configurable delimiter and array handling.
- jsonSearch● ready
Search keys and values in any JSON document with case-sensitive/insensitive toggle. Finds matches in keys, string values, numbers, booleans, and nulls.
- jsonKey Extractor● ready
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.
- jsonSort Keys● ready
Sort every object's keys in a JSON document — ascending (A→Z) or descending (Z→A). Uses your existing JSON parser for error feedback.
- jsonEscape● ready
Escape a raw string for embedding in JSON (e.g. newlines become \n), or unescape an escaped JSON string back to plain text.
- jsonDup Keys● ready
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.
- jsonYAML → JSON● ready
Parse YAML text and produce equivalent JSON using the js-yaml library. Works with any valid YAML 1.2 document.
- jsonJSON → XML● ready
Transform JSON documents into well-formed XML. Arrays become repeated elements; nested objects become nested elements.
- jsonXML → JSON● ready
Convert well-formed XML into equivalent JSON objects. Repeated child elements become arrays; attributes are prefixed with @.
- jsonSize Analyzer● ready
Measure your JSON's byte size and see which keys are bloating it. This free JSON size calculator breaks down every path's contribution with absolute size, percentage, and a visual bar — all in your browser.
- jsonJSON → SQL● ready
Convert a JSON array of objects into SQL table definitions and INSERT statements. Type inference, table naming, and optional DROP TABLE prefix.
- jsonJSON → MD Table● ready
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.
- jsonArray Stats● ready
Analyze arrays of objects and get per-field stats: min, max, avg, unique count, null count, top values, and type inference.
- jsonCircular Ref● ready
Detect and report circular references in JSON data that would cause JSON.stringify to throw a TypeError.
- jsonArray → Object● ready
Transform an array of objects into a key-indexed object (like Lodash keyBy) or go the other direction — object back to array.
- jsonJSONC → JSON● ready
Remove // and /* */ comments plus trailing commas from JSONC/JSON5 files to produce strict RFC 8259 JSON.
- jsonJSON → GraphQL● ready
Paste a JSON object and get a GraphQL schema with inferred types — nullable or required.
- jsonJSON Line Numbers● ready
A lightweight JSON viewer with a synchronized line-number gutter. Paste JSON and see every line numbered.
- jsonJSON for Chat● ready
Generate chat-ready JSON snippets — auto-split into multiple messages to fit platform character limits.
About JSON Tools
Whether you are debugging an API response, building a JSONPath query, checking a payload's byte size, or converting between CSV and JSON, our JSON utilities run locally, are keyboard accessible, and never upload your data. The suite covers the full workflow: format and validate, diff two documents, navigate with JSONPath, generate schema and mock data, and convert between JSON, CSV, YAML, XML, SQL, and TypeScript types.
Related guides
Related categories
Frequently asked questions
What is JSON?
JSON (JavaScript Object Notation) is a lightweight, text-based data format built on key/value pairs and arrays. It is the de-facto format for web APIs.
What's the difference between JSON and CSV?
JSON is a nested, typed data format for APIs and structured payloads, while CSV is a flat, tabular format best opened in spreadsheets. JSON handles nested objects and arrays natively; CSV requires flattening. For tabular data that humans need to inspect, CSV is often easier — for machine-to-machine data, JSON is the standard. Use the CSV to JSON or JSON to CSV converters to move between them.
Why does my JSON keep failing to validate?
The most common causes are trailing commas, unquoted or single-quoted keys, and control characters inside strings. JSON also requires double quotes around every key, and duplicate keys are technically allowed but almost always a bug. The JSON Validator reports the exact line and column of the first error so you can fix it fast.
Is JSON the same as JavaScript?
No. JSON is a strict, language-independent text format. All JSON is also valid JavaScript, but JavaScript objects can include functions and symbols that JSON cannot represent.