YAML to TOML Converter
Convert YAML configuration files to TOML (Tom's Obvious, Minimal Language) format. Perfect for migrating Kubernetes, Docker Compose, or CI/CD configs to Rust, Python, and Go projects that use TOML.
Conversion Options
TOML doesn't support nulls
Standard is 2 spaces
Recommended Settings
TOML Best Practices
- •Use 2-space indentation for nested structures (TOML standard)
- •TOML is perfect for config files - human-readable and unambiguous
- •Blank lines between sections improve readability for large configs
- •TOML doesn't support null values - always skip or remove them
- •Arrays of objects become [[section]] syntax in TOML automatically
YAML to TOML Migration Tips
- •YAML nested objects become TOML tables with [section.subsection] syntax
- •YAML arrays of objects convert to TOML array of tables [[section]]
- •YAML comments are lost - add them manually in TOML output if needed
- •Sort keys alphabetically for consistent output and easier diffs
- •Use TOML for Rust (Cargo.toml), Python (pyproject.toml), and Go configs
Pro Tips
- •All conversion happens client-side - your configuration data never leaves your browser
- •TOML is commonly used in Rust (Cargo.toml), Python (pyproject.toml), and Go projects
- •Blank lines between sections make large TOML files more scannable
- •YAML anchors and aliases are resolved during conversion - TOML doesn't support them
Most Popular
Skip null values with blank lines between sections for clean, readable TOML configs
When to Use This Tool
Convert YAML configs to Cargo.toml format for Rust projects. Cargo uses TOML for dependencies, build settings, and package metadata. Transform your YAML configs to idiomatic Cargo.toml with proper sections and formatting.
Generate pyproject.toml from YAML for modern Python projects. PEP 518 uses TOML for build systems and tool configuration. Convert YAML configs to pyproject.toml for poetry, black, mypy, and other Python tools.
Transform YAML to TOML for Go application configuration files. Many Go projects use TOML (via libraries like viper or spf13) for cleaner, more structured configs compared to YAML's indentation-based syntax.
Migrate from YAML-based configs (Kubernetes, Docker Compose) to TOML for consistency across your development tools. TOML provides unambiguous syntax without indentation sensitivity, reducing configuration errors.
Convert YAML front matter or configs to TOML for Hugo sites. Hugo supports both formats but TOML is the default. Transform your YAML site configs, theme settings, or front matter to idiomatic Hugo TOML.
Migrate existing YAML configuration files to TOML when adopting new tools or frameworks. TOML's explicit syntax and clear table structure make configs easier to validate and less prone to indentation-related parsing errors.
How It Works
Parse YAML input using js-yaml library
Validate YAML syntax and structure
Check that root is an object (TOML requirement)
Detect and handle null values (skip or error)
Sort object keys alphabetically if option enabled
Convert YAML nested objects to TOML table syntax [section]
Transform YAML arrays of objects to TOML array of tables [[section]]
Apply formatting options (indent size, blank lines)
Generate TOML output using json2toml library
Copy to clipboard or download as config.toml file
100% Private
Files never leave your device. All processing happens locally in your browser.
Lightning Fast
Powered by Pure JavaScript for optimal performance on modern browsers.
Secure
No data collection, no tracking, no sign-up required.
Frequently Asked Questions
Why doesn't TOML support null values?
TOML specification intentionally excludes null to keep the language simple and unambiguous. If a value is missing or unknown, simply omit the key entirely. The 'Skip null values' option automatically removes nulls from your YAML during conversion.
How are YAML nested objects converted to TOML?
YAML nested objects with indentation become TOML table syntax with square brackets. For example, 'database: host: localhost' becomes '[database]' followed by 'host = "localhost"'. Deeply nested structures use dotted table names like [database.connection.pool].
What happens to YAML arrays of objects?
YAML arrays of objects convert to TOML array of tables using double square brackets [[section]]. For example, a YAML 'servers' array with multiple server objects becomes '[[servers]]' entries in TOML, each representing one array element.
Can I convert Kubernetes YAML to TOML?
Yes, but TOML is not suitable for Kubernetes manifests - Kubernetes only accepts YAML/JSON. This tool is best for converting Kubernetes configs to application configs in TOML format (like Cargo.toml or pyproject.toml), not for running in Kubernetes.
What happens to YAML comments?
YAML comments (lines starting with #) are lost during conversion because the intermediate JavaScript object doesn't preserve comments. TOML supports comments, so you'll need to add them manually in the TOML output if documentation is important.
How are YAML anchors and aliases handled?
YAML anchors (&name) and aliases (*name) are automatically resolved during parsing. The js-yaml library expands all references, so the TOML output contains the full data structure. TOML doesn't have anchor/alias features, so values are duplicated.
When should I use blank lines between sections?
Enable blank lines for large config files with many sections - it improves readability and makes it easier to scan the file. For small configs with 2-3 sections, you can disable it for more compact output. Most TOML style guides recommend blank lines.
Is my configuration data secure during conversion?
Absolutely! All conversion happens entirely in your browser using client-side JavaScript. Your YAML configs (even sensitive ones like database credentials) never leave your computer or get sent to any server. The tool works completely offline after the page loads.