Why TOML exists alongside YAML and JSON

TOML was designed with an explicit goal that neither YAML nor JSON fully achieves: being obvious to a human reading it and unambiguous to a machine parsing it, specifically for hand-edited configuration files. JSON has no comments and is punctuation-heavy for hand-editing; YAML's indentation sensitivity and permissive type coercion (where an unquoted `yes` or `no` can silently become a boolean) have caused real, well-documented bugs. TOML's design leans on a flat key=value syntax with explicit `[table]` headers for nesting, which is part of why it became the standard for tool configs like Cargo.toml (Rust) and pyproject.toml (Python) — it optimizes specifically for the case of a person writing and editing the file directly, which is exactly the case this tool is aimed at helping with.

Why converting to JSON is the fastest way to check a parse

Seeing the parsed result as JSON is a fast, unambiguous way to confirm the parser understood a TOML file the way you intended — nested tables, arrays of tables, and dotted keys all have specific TOML syntax rules that are easy to get subtly wrong, and the quickest way to catch a misunderstanding is seeing the actual resulting structure rather than just a pass/fail on syntax. If a `[servers.alpha]` table header didn't nest the way you expected, or an array of tables didn't accumulate the way you thought it would, the JSON view makes that immediately visible rather than requiring you to mentally trace the TOML rules yourself.