Nine Useful JSON Validation and Formatting Tools

JSON (JavaScript Object Notation) is a lightweight data‑interchange format widely used by developers and machines. Numerous tools have been created to validate, format, compare, and edit JSON, ranging from online services to IDE plugins and command‑line utilities.

1. JSONLint

JSONLint, provided by CircleCell, is an online validator and formatter. Users can paste JSON, provide a URL, or use the ?reformat=compress query to compress JSON. It also offers a GitHub repository for its source code.

URL: https://jsonlint.com/

Source: https://github.com/circlecell/jsonlint.com

2. JSONCompare

JSONCompare extends JSONLint with batch validation, comparison, and merging of multiple JSON files. It supports simple, batch, and diff modes, and is also developed by CircleCell.

URL: https://jsoncompare.com/

Source: https://github.com/circlecell/jsoncompare.com

3. jtc

jtc (JSON Test Console) is a CLI tool for extracting, processing, and transforming source JSON. It allows selecting elements, wrapping them into new JSON, filtering, or updating, and provides massive changes via single commands. Binaries are available for Linux and macOS.

Download: https://github.com/ldn-softdev/jtc#compile-and-install-instructions

4. ijson

ijson is a Python iterator‑based streaming JSON parser that generates native Python objects from JSON streams. It offers C‑based (YAJL) and pure‑Python back‑ends.

Download: https://pypi.org/project/ijson/#files

5. JSON Formatter & Validator

This online tool formats and beautifies JSON for easier reading and debugging. Users can paste JSON or provide a URL, and the tool can also validate public JSON URLs.

URL: https://jsonformatter.curiousconcept.com/

6. Altova XMLSpy JSON and XML Editor

Altova XMLSpy is a commercial editor supporting both JSON and XML, offering schema design, code generation, conversion, debugging, and validation via RaptorXML Server.

Download (free trial): https://www.altova.com/xmlspy-xml-editor/download

7. Code Beautify JSON Tools

Code Beautify provides a suite of JSON utilities, including viewer, editor, validator, and converters to HTML, XML, YAML, as well as an Excel‑to‑JSON converter and minifier. It also supports many other data formats.

URL: https://codebeautify.org/json-tools

8. Visual Studio Code

Microsoft's VS Code includes built‑in JSON support with IntelliSense, validation, navigation, code folding, and context‑aware suggestions based on associated JSON schemas.

Download: https://code.visualstudio.com/Download

9. Eclipse JSON Editor Plugin

The free Eclipse plugin adds custom syntax highlighting, code folding, formatting, and a synchronized tree view for JSON, complying with RFC 4627.

Download: https://marketplace.eclipse.org/content/json-editor-plugin