The Ultimate JSON Swiss Army Knife
Format, validate, and transform your JSON with desktop-grade performance — 100% client-side and secure.
FAQ
Is it safe to format JSON online?
Yes, provided the tool runs 100% client-side. JSON Nova processes all data locally in your browser. Your sensitive JSON payloads are never transmitted to any server, making it safe for production data.
How do I fix an 'Unexpected Token' error?
This usually points to a syntax mistake like a missing comma between objects, an extra closing bracket, or a semicolon where a comma should be. Use our 'Format / Repair' button to auto-fix common mistakes.
Why does my JSON fail when using single quotes?
The JSON standard strictly requires double quotes for keys and string values. Single quotes are common in JavaScript but invalid in JSON. Our editor highlights these errors to help you fix them instantly.
Can I convert JSON to TypeScript interfaces?
Absolutely! JSON Nova includes a built-in TypeScript generator. Just paste your JSON and select 'To TypeScript' from the Tools menu to get perfectly typed interface definitions for your project.
Is there a limit to the JSON file size?
JSON Nova is built on the Monaco Editor engine, allowing it to handle large files up to 50MB with ease. For extremely large files, it uses web workers to ensure your browser remains responsive.
Does formatting JSON change the actual content?
No. Formatting (or 'pretty-printing') only adds whitespace and indentation to make the data human-readable. The underlying data structure and values remain exactly the same as the original input.
Does JSON Nova support XML to Class conversion?
Yes! Our 'Data to Class Hub' supports both JSON and XML source formats. You can convert XML schemas directly into Java classes, Rust structs, Go models, and many other professional programming formats.
Which programming languages are supported?
We support over 18+ major programming languages, including Java, Python, Rust, Go, C#, Swift, C++, TypeScript, Kotlin, Ruby, Dart, Haskell, Elm, Flow, Objective-C, and more. Each target uses idiomatic naming conventions and serialization attributes.
How is Null Safety handled in generated code?
Our generators are designed for professional use. We use language-specific features like Optional in Java, Option<T> in Rust, Maybe in Haskell/Elm, and Nullable types in C# and Kotlin to ensure your models are safe and robust.