8 Free Online JSON Tools (2026)
- 02 Oct 2026
JSON is one of the most common data formats used in modern software development, particularly when working with APIs, configuration files, and data exchange.
Whether you need to validate a JSON document, make it easier to read, explore a complex structure, compare two responses, or convert JSON into another format, there are plenty of free online tools that can help.
So here's a collection with 8 of the best free online JSON tools worth bookmarking in 2026.
1. JSONViewer.tools
This tool provides several utilities for working with JSON data. It allows you to load JSON and explore its structure as a tree, making it easier to navigate complex and deeply nested objects.
The site also includes additional JSON conversion utilities in its Converter section.
2. JSON Formatter & Validator
https://jsonformatter.curiousconcept.com/
JSON Formatter & Validator can identify common JSON syntax problems and helps you turn unformatted JSON into a more readable and organized structure by automatically applying indentation and formatting.
3. JSONLint
JSONLint is a simple online JSON validator and formatter. Paste your JSON into the tool to check whether it is syntactically valid and format it into a more readable structure.
The site also provides a JSON Stringify utility that converts a JSON object into an escaped JSON string.
4. JSON Crack
JSON Crack provides an interactive visual representation of JSON data. Instead of navigating through a large JSON document line by line, you can use a graphical representation to see the relationships between objects and nested nodes.
This can be particularly helpful when working with complex JSON structures that are difficult to understand in their raw form.
5. JSON Hero
JSON Hero is a JSON viewer designed to make large and complex JSON documents easier to explore. It provides different ways to view your data, including column, tree, and JSON views. It also provides search capabilities and contextual previews for certain types of values.
The column view can be particularly useful for navigating deeply nested data, while the tree view provides a more traditional hierarchical representation.
6. JSONDiff
JSONDiff is designed to compare two JSON documents. It can validate and format JSON while also showing the differences between two JSON structures. This makes it useful when you need to determine what changed between two API responses, configuration files, or JSON documents.
Unlike a simple text comparison, JSONDiff is designed to compare the structure of the JSON objects rather than simply comparing lines of text.
7. JSON to CSV Converter
Konklone provides a simple way to convert JSON data into CSV format. This can be particularly useful when you have JSON data that you want to analyze in a spreadsheet application such as Excel or Google Sheets.
8. JSONLint JSON Stringify
https://jsonlint.com/json-stringify
JSONLint also provides a dedicated JSON Stringify utility for converting JSON objects into escaped JSON strings.
This can be useful when JSON needs to be embedded as a string inside another JSON document, request body, configuration, or piece of code.
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