YAML to TOML Converter — Free Online YML to TOML Tool

YAML to TOML Converter — Free Online YML to TOML Tool. Free online YAML to TOML converter.

Convert YAML or YML config files to clean TOML tables and arrays of tables, with anchors and merge keys, null handling, sorted keys and line-precise errors — 100% in your browser.

Our free YAML to TOML converter turns any YAML or YML configuration into valid TOML as you type.

Paste a Hugo or Jekyll site config, a GitHub Actions snippet, an application settings file or a list of dependencies and convert YAML to TOML instantly: nested mappings become [tables] and [sub.tables], lists of objects become [[arrays.of.tables]], and strings, integers, floats and booleans keep their types.

Anchors, aliases and << merge keys are resolved first, so the generated TOML is ready for Cargo.toml, pyproject.toml, Hugo, Netlify or any other tool that reads TOML.

TOML vs YAML: both are human-friendly config formats, but TOML is stricter — it has no null value and its top level must always be a table.

This YAML to TOML online tool handles those differences for you: choose whether null values are dropped or written as empty strings, get a clear message when the YAML root is a list or a scalar, and see the exact line and column of any YAML syntax error.

Turn on key sorting for stable, diff-friendly output. Need the opposite direction? Use our TOML to YAML Converter. Starting from JSON instead? Try JSON to TOML.

All conversion runs locally in your browser, so secrets, hostnames and credentials in your configuration files are never uploaded, and the converter keeps working offline once the page has loaded.

Load the sample manifest to see tables and arrays of tables, copy the TOML with one click, download it as config.toml, or share a link that restores your YAML and options. Related tools: YAML to JSON Converter, TOML to JSON and YAML Viewer.

Frequently asked questions

How do I convert YAML to TOML?

Paste your YAML into Your YAML or click Load sample. TOML from your YAML updates as you type; click Copy TOML, or Download .toml to save it as config.toml.

How are nested objects and lists converted to TOML?

Nested mappings become TOML tables such as [server.tls], lists of simple values become arrays, and lists of mappings become arrays of tables written with double brackets, like [[plugins]]. Anchors and merge keys are resolved first.

What happens to null values?

TOML has no null type. Set Null values to Drop (the default) to leave those keys out, or to Empty string to keep them as empty strings. Turn on Sort keys alphabetically to order keys in every table.

Why do I get an error that TOML needs a mapping at the top level?

A TOML document is always a table of key and value pairs. If your YAML's top level is a list or a single value, put it under a key, for example items:, and it converts.

Is my YAML uploaded when converting to TOML?

No. The conversion runs entirely in your browser, so your configuration files never leave your device.

How to use this online tool

YAML to TOML Converter — Free Online YML to TOML Tool is designed for fast browser workflows when you need to format, validate, convert, decode, encode, generate, or inspect data without opening a heavy desktop app. Start with the input field or visible options, review the result, then copy or download the output for the next step.

Private processing in your browser

YAML to TOML Converter — Free Online YML to TOML Tool keeps the normal processing step local in your browser. That is useful for code snippets, tokens, documents, configuration values, text samples, and other material that should not be sent to a remote service unless you explicitly choose to share it.

When this tool is useful

Use YAML to TOML Converter — Free Online YML to TOML Tool for repeatable developer tasks, technical documentation, QA checks, quick conversions, debugging, content cleanup, and internal team workflows. The page focuses on clear inputs, immediate feedback, and output that is easy to reuse in code, reports, tickets, emails, or notes.

Practical tips

Before copying the final result, check important details such as spacing, casing, filenames, encoding, token structure, line breaks, or output format. Small checks prevent mistakes when the result is reused in source code, API requests, documentation, spreadsheets, or shared files.