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TOML Formatter & Validator

Format, validate, and convert TOML to JSON or JSON to TOML. Runs entirely in your browser.

Input TOML

Formatted TOML

Tip: Use the Format TOML tab to validate and pretty-print TOML. Switch to TOML → JSON to convert your config to JSON, or JSON → TOML to go the other way.

About TOML Formatter & Validator

Working with code and configuration files often means switching between formats, encoding strings, or validating syntax. TOML Formatter & Validator eliminates the need for desktop software or command-line utilities by giving you a clean, instant interface right in your browser. Paste your input, get your result — no accounts, no installations, no data leaving your machine.

How to Use

Enter or paste your input Type or paste your data into the input area. You can also use keyboard shortcuts (Ctrl+V) for quick pasting.

Configure options Adjust any settings or options above the input area to customize the output format and behavior.

Process your data Click the primary action button to process your input. The result appears instantly — no server round-trips.

Review the output Check the output area for your processed result. Any errors or warnings will be displayed clearly.

Copy or download Use the Copy button to copy the result to your clipboard, or download it as a file if that option is available.

🔒 Privacy note: All processing happens locally in your browser. Your data is never sent to any server.

Why Use TOML Formatter & Validator?

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Instant Results, Zero Setup No need to install CLI tools, configure environments, or write scripts. TOML Formatter & Validator gives you the result instantly in your browser — paste, click, done.

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Your Code Stays Private All processing runs locally using JavaScript. Your source code, API keys, tokens, and configuration data never leave your browser — not even temporarily.

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Part of Your Dev Workflow Bookmark this tool alongside your IDE and terminal. When you need a quick format, encode, or validation, it's one tab away — faster than installing yet another npm package.

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Use It Anywhere Works on any device with a modern browser — laptop, tablet, or phone. Perfect for quick fixes when you're away from your development machine.

Frequently Asked Questions

TOML (Tom's Obvious, Minimal Language) is a configuration file format designed to be easy to read. It's used by Rust's Cargo, Python's pyproject.toml, Hugo, and many other tools.

This tool uses the @iarna/toml library (v2.2.5) loaded from jsDelivr CDN. It is a battle-tested TOML parser that supports the full TOML 0.5 specification.

TOML to JSON conversion preserves numbers, strings, booleans, arrays, and tables. TOML datetime types are converted to ISO 8601 strings in JSON. When converting JSON back to TOML, all standard JSON types are supported.