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TOML to JSON

Convert a TOML file to JSON locally - with tables and arrays, no upload, right in your browser.

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Your files never left your device

    Is my file uploaded?

    No. Everything runs in your browser - your file never leaves your device. How this is verifiable

    No upload100% local
    Your content stays with youno third-party access
    Servers in GermanyGDPR by design
    Independently auditedTLS A+ · HTTP headers A+

    TOML is the highly readable configuration format behind tools like Rust's Cargo (Cargo.toml), Python's pyproject.toml and many others. JSON, by contrast, is the format that APIs, scripts and web apps consume directly. This tool parses your TOML into an equivalent JSON object.

    The conversion runs entirely locally in your browser (smol-toml, pure JavaScript). TOML tables become nested objects, arrays of tables become arrays, and date/time values become ISO strings. Very large integers beyond the safe JavaScript range are rejected with a clear message instead of being converted with precision loss. Invalid TOML is rejected with a clear error, and nothing is uploaded.

    You will meet this when evaluating a Cargo.toml or pyproject.toml, loading a config into a script, or passing TOML settings to a frontend. TOML relies on sections in square brackets and plain key-equals-value lines, which keeps config files pleasant for humans to maintain; on conversion that structure survives as nesting in the JSON. The result is indented, readable JSON - ready to use right away.

    Specifications

    Specifications
    Input formatsTOML
    Output formatJSON
    Batch processingNo
    ProcessingLocally in your browser (JavaScript)
    File uploadNone

    In 3 steps

    1. Drop or pick your TOML file.
    2. The tool parses it into JSON.
    3. Download the JSON file.

    Limitations: Supports TOML 1.0: tables, arrays of tables, inline tables, all scalar types and date/time values. Tables become objects, arrays of tables become arrays, date/time values become ISO strings; very large integers beyond the safe JavaScript range are rejected with a clear message (no lossy conversion). Invalid TOML is rejected with a clear error.

    FAQ

    Is my file uploaded?

    No. The conversion runs entirely locally in the browser - nothing is sent.

    Which TOML features are supported?

    TOML 1.0: tables, arrays of tables, inline tables, all scalar types and date/time values.

    How are date/time values handled?

    They are emitted as ISO 8601 strings so they stay valid in JSON.

    Does it work with a Cargo.toml?

    Yes. Cargo.toml, pyproject.toml and other TOML files are parsed directly.

    What happens with invalid TOML?

    You get a clear error message with the cause - no crash.

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