JSON Formatter

What can it do?

While being built into most IDEs we constantly find ourselves googling 'json formatter' or 'json linter' for quickly validating and formatting JSON files. Most of the tools available format JSON by creating a server request. We never want to share JSON with anyone, why we decided to build this free JSON formatter and validator that works without making any server requests.

Input a JSON string in the field above and click the Validate & Format button for quick validation and a nicely formatted JSON output. Besides formatting and checker features, the outputted JSON can be collapsed/expanded for easy navigation and the formatted JSON can be copied directly to the clipboard.

Formatting JSON files are primarily to make them look good and easier for humans to read. As long as a JSON file follows the syntax from the JSON specification, the number of newlines, spaces, etc. doesn't make any difference. JSON is a serialization format and not a presentation format. Pretty much all programming languages have support for JSON either built-in or through a third-party package. Converting objects to JSON from JavaScript is simple using the built-in JSON helper:

JSON.stringify({ hello: "world" });
// produces: "{\"hello\": \"world\"}"

The number of spaces to use for indentation can be configured using options for the stringify function:

JSON.stringify({ hello: "world" }, null, 2)
// produces: "{\n  \"hello\": \"world\"\n}"

Other languages and frameworks have similar options for showing JSON on the screen.