How values carry across
JSON, YAML and TOML all have objects, lists, strings, numbers and true/false, so those convert cleanly. TOML has no null, so empty values are left out and you're told. Dates in YAML and TOML are kept as text in ISO format, so 2026-10-21 stays exactly as written.
XML and .env
XML attributes become keys starting with @, text next to child elements goes under #text, and repeated elements become a list. Going back to XML follows the same rules. A .env file is a flat list of names and values, so nested data is flattened into names like DATABASE_HOST, and lists are joined with commas. Quoted values, export lines, inline comments and multi-line values in double quotes are understood.
Error messages that help
Every parser reports the line and column where it got stuck, such as a missing comma in JSON, a tab or a bad indent in YAML, a duplicate key in TOML or a tag that doesn't close in XML. Press Show the line to jump straight to it.