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TOML Validator

TOML Validator

Validate TOML and re-emit it as clean, indented JSON

TOML Input

About

Paste a TOML document to validate it against the TOML spec and pretty-print the parsed result as indented JSON. Handy for Cargo.toml, pyproject.toml, and config files. Everything runs in your browser; nothing is uploaded.

    About this tool

    Validate TOML (Cargo.toml, pyproject.toml) and pretty-print it as JSON. Catch syntax errors fast. Free, client-side, no signup. TOML Validator runs in the browser on DevTools. There is no signup, and your input stays on this device unless the tool explicitly performs a live network lookup.

    What this tool does not do

    • TOML Validator is a free in-browser utility, not a hosted API. It does not keep server-side history and is not a substitute for production verification in your own stack.

    How do I use this tool?

    1. How do I use TOML Validator?

      Open TOML Validator, enter or paste your input, and copy the result. The page works without an account.

    Related guides

    TOML vs YAML vs JSON: Choosing the Right Config Format

    Why Rust and Python both settled on TOML, what each format actually gives you, and how to validate your Cargo.toml without guessing.

    Moving Configuration Between TOML, JSON and YAML: What Survives the Trip

    Converting config formats sounds trivial until your dates vanish, your comments disappear, and your multiline string gets folded into one line.

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