What does this tool do?
This tool converts your YAML configuration into TOML format. It maps YAML's nested mappings and lists onto TOML's tables, arrays and key-value syntax, giving you output ready for tools like Rust's Cargo, Python's pyproject.toml or Hugo. Everything runs entirely in your browser.
How to use it
- Paste or type your data into the left field.
- The result is generated instantly on the right.
- Use the Copy button to grab the output.
Why teams choose TOML
TOML stands for 'Tom's Obvious Minimal Language' and is purpose-built for configuration files. Unlike YAML's indentation sensitivity, TOML uses explicit bracketed table headers, which improves readability in deeply nested structures and eliminates whitespace errors. Cargo for Rust, Poetry and pyproject.toml for Python, Hugo and many modern tools expect their configuration in TOML. Converting a structure you authored in YAML to TOML lets you move smoothly into these ecosystems without rewriting everything by hand.
How the mapping works
Our converter turns YAML mappings into TOML tables, lists of objects into arrays of tables (the [[ ]] syntax), and simple sequences into inline TOML arrays. Types such as dates, numbers and booleans are preserved. However, TOML expects key-value pairs and tables at the top level, so a YAML document whose root is a bare list or scalar cannot be mapped directly. In those cases you need to nest the data under a named key before conversion succeeds.
Frequently asked questions
How do nested YAML objects appear in TOML?
Each nested mapping becomes a bracketed table header in TOML, such as a dotted header like 'database.connection'. Lists made of objects are mapped to arrays of tables using the [[item]] form.
Can every YAML document be converted to TOML?
No. TOML expects a table of key-value pairs at the root. A YAML file whose top level is a single list or scalar value cannot produce valid TOML unless it is first wrapped under a key.
What happens to comments and null values?
YAML comments are not preserved in the conversion, though TOML does support '#' comments. TOML has no null type, so null values are dropped or must be represented as an empty string instead.
Is YAML to TOML free?
Yes. YAML to TOML and all 300+ tools on MagmaNex are completely free with no signup or account required.
Is my data safe?
Yes. Everything runs locally in your browser. The data you enter is never sent to a server, stored, or shared.
Does it work on mobile?
Yes. YAML to TOML works on phones, tablets and desktops — no app download needed.
🔒 Privacy: everything runs in your browser, your data is never sent to a server.