API Response Debugging
Paste a raw API response into the JSON Formatter to pretty-print and validate syntax. When two environments return "different" data, the JSON Diff surfaces the exact field-level delta without scrolling thousands of lines.
Every JSON Tool You Need, in One Place
Format, validate, diff, convert, and query JSON without sending anything to a server. Five tools, one consistent interface.
All JSON Tools
JSON Formatter
Format and validate JSON against RFC 8259 rules, catch single quotes, unquoted keys, and syntax errors instantly. Free private browser-based tool.
JSON Diff
Compare two JSON objects side by side and export JSON Patch (RFC 6902) with JSON Pointer paths for add, replace, remove, move, copy, and test operations.
JSON Schema Validator
Validate JSON data against a JSON Schema (Draft 7) with detailed error reporting. Free browser-based tool with example buttons and path-level diagnostics.
JSON Converter
Convert between JSON, YAML, CSV, and XML formats instantly. Free browser-based tool with bidirectional conversion, no registration required.
JSONPath Query
Query and extract data from JSON using JSONPath expressions. Supports recursive descent, wildcards, filters, and array slicing. Free online tool.
Why a Dedicated JSON Hub?
JSON is the common currency of modern APIs, configuration files, CI/CD pipelines, and data interchange. Poorly formatted JSON blocks deploys. Schema mismatches cause silent failures. Two files that "look identical" often differ in a single nested value that only a structural diff can reveal. This hub consolidates the five purpose-built JSON tools we ship so you can pick the right one for the job — and deep-dive articles that explain the underlying standards (RFC 8259, JSON Schema, JSONPath).
Common JSON Workflows
Contract-Testing Against JSON Schema
Use the JSON Schema Validator to verify a producer response matches its contract. Catches additive regressions, type narrowings, and required-field omissions that break consumers silently.
Configuration Migration
Convert YAML configs to JSON (or back) with the JSON Converter. Preserves arrays, nested objects, and multi-line strings across formats used by tools like Kubernetes, GitHub Actions, and Ansible.
Data Extraction from Large Payloads
Query a nested JSON document with JSONPath expressions in the JSONPath Query tool — like XPath for JSON — to pull exactly the fields you need without writing JavaScript.
The JSON Standards in 90 Seconds
RFC 8259 is the current authoritative specification for JSON. It mandates UTF-8 encoding, disallows comments, requires strict number formatting (no leading zeros, no infinity), and enforces specific escape sequences in strings. Our JSON Formatter applies RFC 8259 strictly; the relaxed JSON5 superset (with trailing commas and comments) is supported as a pre-processing step before strict normalization.
JSON Schema (current draft: 2020-12) is a separate standard for describing the shape of a JSON document. It supports type constraints, nested objects, array item validation, and conditional logic. Most API vendors now publish schemas alongside their OpenAPI definitions.
JSONPath (RFC 9535, standardized in 2024) is to JSON what XPath is to XML: a concise query language for extracting values from nested structures. Our query tool implements the RFC-compliant subset suitable for most real-world extraction tasks.
JSON Guides & Deep Dives
- How to Filter Arrays with JSONPath: Practical Examples for Real JSON Data Learn how to filter JSON arrays with JSONPath using equality, numeric comparisons, nested fields, existence checks, and real API examples.
- Using JSONPath in JavaScript, Python, and Java: Libraries, Syntax, and Pitfalls Compare JSONPath libraries in JavaScript, Python, and Java, including syntax differences, return modes, filters, and portability pitfalls.
- JSONPath vs JMESPath vs SQL/JSON: Choosing the Right JSON Query Language Compare JSONPath, JMESPath, and SQL/JSON by syntax, filters, portability, and real-world use cases in APIs, cloud tooling, and databases.
- Comparing JSON Objects: Techniques for API Debugging and Config Management Learn how to compare JSON objects effectively for API debugging, config management, and CI/CD pipelines. Covers deep diff, JSON Patch, and best practices.
- Converting Between JSON, YAML, CSV, and XML: A Practical Guide to Data Format Conversion Learn how to convert data between JSON, YAML, CSV, and XML formats. Understand conversion challenges, data loss risks, and best practices for each format.
- JSON Patch RFC 6902 Guide: Add, Replace, Paths, and Target Rules Understand JSON Patch RFC 6902 fast: add inserts before array indexes, replace requires the target path to exist, and paths use JSON Pointer RFC 6901.
- Real-World JSON Schema Examples: Practical Patterns for APIs, Configs, and Catalogs Explore practical JSON Schema examples for user registration APIs, product catalogs, app configs, and CI/CD pipelines with reusable patterns.
- JSON Schema Validation: A Complete Guide to Validating JSON Data Learn JSON Schema Draft 7 validation including types, required fields, patterns, and composition keywords. With practical examples for API contracts.
- JSONPath Query Syntax Guide: Expressions, Filters, and Practical Examples Learn JSONPath syntax for querying JSON data: root, child, recursive, wildcard, filters, slicing, and real-world examples compared with XPath and jq.
- YAML vs JSON: When to Use Which Format for Configuration, APIs, and Infrastructure Compare YAML and JSON across syntax, readability, security, and tooling. Learn when each format excels for APIs, Kubernetes, CI/CD, and configuration files.
- JSON Best Practices for API Development: Responses, Errors, and Performance Practical JSON API best practices: response envelopes, naming conventions, error formats, pagination, versioning, security, and performance for REST APIs.
- Understanding JSON: Structure, Syntax, and Common Errors Explained Complete guide to JSON syntax, data types, common parsing errors, and how JSON compares to YAML, XML, and other formats. With code examples.
Privacy: Your JSON Never Leaves Your Browser
Every tool in this hub processes input client-side using JavaScript. Your payloads — whether a 20-line config or a 50MB API dump — are never sent to a server, logged, or stored. Close the tab and nothing remains. This matters because JSON commonly contains credentials, PII, internal URLs, and other data that should not be copy-pasted into third-party web tools.