DevToolbox

JSON Formatter & Validator

Paste your JSON to format, validate, and beautify it instantly.

About This Tool

The JSON Formatter & Validator is a free browser-based tool that helps developers quickly format, validate, minify, and explore JSON data. Whether you're debugging an API response, cleaning up a config file, or inspecting deeply nested structures, this tool makes working with JSON effortless.

All processing happens entirely in your browser using native JavaScript APIs. Your data never leaves your machine — there are no server round-trips, no logging, and no third-party analytics on your input. This makes it safe for sensitive payloads such as authentication tokens, internal API responses, and configuration files containing secrets.

The formatter supports lenient input: you can paste JSON that contains single-line (//) or multi-line (/* */) comments, as well as trailing commas. These are automatically stripped before parsing so you can work with real-world config files (like tsconfig.json) without manual cleanup.

The interactive tree view lets you explore deeply nested objects and arrays by collapsing and expanding nodes. Clicking any node copies its JSON path (e.g. $.data.users[0].email) to your clipboard, which is handy when constructing queries or referencing fields in code. The path search bar filters the tree to help you locate specific keys in large documents.

How to Use

  1. Paste or type your JSON into the Input panel.
  2. The output updates automatically. Use the Format, Minify, or Tree tabs to switch views.
  3. In Format mode, toggle between 2-space and 4-space indentation with the badges.
  4. In Tree mode, click any node to copy its JSON path. Use the search bar to filter paths.
  5. Click Copy to copy the output, or Clear to reset both panels.
  6. Keyboard shortcuts: Ctrl+Enter to re-process, Ctrl+Shift+C to copy output.

FAQ

Is my data safe?

Yes. All parsing and formatting is done client-side with JavaScript's built-in JSON.parse and JSON.stringify. No data is sent to any server.

Can it handle large JSON files?

The tool works well with files up to several megabytes. For inputs larger than 1 MB a warning is shown, as processing may slow down depending on your device.

What happens with invalid JSON?

An error message is displayed with the parser's description of the problem, including the position where parsing failed, so you can quickly locate and fix the issue.

Does it support comments and trailing commas?

Yes. Single-line (//) and multi-line (/* */) comments are stripped before parsing. Trailing commas before } or ] are also removed automatically.

What is JSON path search?

In Tree mode, the search bar filters nodes by their path (e.g. users.email). Matching nodes are highlighted so you can quickly find specific keys in large documents.

What keyboard shortcuts are available?

Ctrl+Enter re-processes the input and Ctrl+Shift+C copies the formatted output to your clipboard.

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