Nine Useful JSON Validation and Formatting Tools

JSON is widely appreciated for being easy for developers to use and straightforward for machines to parse and generate, leading to a variety of tools for reformatting, validation, and parsing.

1. JSONLint

JSONLint, from CircleCell, is an online validator and formatter where users can paste JSON, input a URL, and even compress JSON by adding ?reformat=compress to the URL.

2. JSONCompare

JSONCompare, an advanced version of JSONLint, validates JSON directly, supports batch uploads, compares and merges two JSON objects, and offers simple, batch, and diff modes.

3. JTC

JTC (JSON Test Console) is a CLI tool that extracts, processes, and transforms source JSON, allowing element selection, wrapping, filtering, and updating via single commands, with binaries available for Linux and macOS.

4. ijson

ijson, created in 2016, provides an iterative JSON parser with a standard Python iterator interface, generating native Python objects from JSON streams using either a C‑based YAJL backend or a pure‑Python backend.

5. JSON Formatter and Validator

This online tool formats and beautifies JSON for easier reading and debugging, accepting JSON or URLs and offering a bookmarklet for public JSON URLs.

6. Altova XMLSpy JSON and XML Editor

Altova XMLSpy supports JSON and XML editing, modeling, transformation, and debugging, featuring graphical schema designers, code generators, converters, and validators that leverage RaptorXML Server for JSON validation.

7. Code Beautify JSON Tools

Code Beautify offers a JSON viewer, editor, validator, and converters to HTML, XML, YAML, as well as an Excel‑to‑JSON converter and a minifier, plus similar utilities for other data formats.

8. Visual Studio Code

VS Code includes built‑in JSON support with IntelliSense validation, navigation, code folding, and context‑aware suggestions, using associated JSON schemas to understand file structure.

9. Eclipse JSON Editor Plugin

The free Eclipse plugin provides custom syntax highlighting, code folding, formatting, a synchronized tree view, and syntax‑tree parsing, complying with the RFC 4627 JSON standard.