How are TOML tables converted to YAML?

TOML tables [section] become YAML mappings with nested indentation. For example, [database] with host = "localhost" becomes a YAML mapping with the database key containing a nested host key.

How are arrays of tables handled?

TOML arrays of tables [[servers]] become YAML sequences (lists). Each [[servers]] entry becomes a list item with a - prefix, following standard YAML list syntax.

Yes. All processing happens entirely in your browser. Your TOML and YAML content is never sent to any server. No data is collected, stored, or transmitted.

TOML to YAML Converter Online - Convert TOML Config to YAML

TOML Input

YAML Output

What is TOML to YAML Converter?

TOML and YAML are both human-readable configuration formats, but they belong to different ecosystems. TOML is the standard for Rust's Cargo.toml and Python's pyproject.toml, emphasizing explicit structure with [table] and [[array_of_tables]] headers. YAML dominates infrastructure-as-code tools like Kubernetes, Docker Compose, and GitHub Actions, using indentation-based nesting. This converter bridges the two worlds: it parses TOML into an internal representation and emits properly indented YAML, or takes YAML and produces valid TOML with correct section headers and type serialization. The bidirectional toggle lets you switch directions without changing tools.

How to Use

Use the direction toggle to choose TOML → YAML or YAML → TOML conversion.
Paste your TOML or YAML content into the input area.
Click 'Convert' to parse the input and generate the output in the target format.
Review the output — YAML uses indentation for nesting, while TOML uses [section] headers.
Copy the result and use it in your Cargo.toml, pyproject.toml, Kubernetes manifest, or Docker Compose file.

Why Use This Tool?

Convert Cargo.toml and pyproject.toml to YAML for use in CI/CD pipelines and Docker Compose configurations

Transform Kubernetes YAML into TOML for Rust or Python tools that require TOML input

Bidirectional conversion eliminates the need for separate tools — toggle between directions instantly

Full support for tables, arrays of tables, inline tables, dotted keys, and all primitive types

Browser-only processing keeps your configuration files private — nothing is uploaded or stored

Tips & Best Practices

TOML tables [section] become YAML mappings with nested indentation — the section name becomes the parent key.
TOML arrays of tables [[servers]] become YAML sequences with the - prefix, which is the standard way to represent lists of objects.
When converting YAML to TOML, strings that could be misinterpreted as numbers or booleans are automatically quoted.
YAML's permissive type coercion (yes/no/on/off as booleans) is handled correctly when converting to TOML's strict types.
Top-level keys in YAML become [sections] in TOML — plan your YAML structure for clean TOML output.

Frequently Asked Questions

How are TOML structures mapped to YAML?

TOML tables [section] become YAML mappings with nested indentation. Arrays of tables [[servers]] become YAML sequences (lists) with - prefix items. Inline tables {key = value} become compact YAML mappings. Dotted keys (a.b.c) create the same nested structure as explicit [a.b] sections.

When should I NOT use this converter?

Avoid this tool when your TOML uses features with no YAML equivalent — such as TOML's strict type distinctions between local dates, local times, and full datetimes, which all become strings in YAML. Also, very deeply nested TOML may produce YAML that is harder to read than the original due to deep indentation.

Can I convert YAML back to TOML?

Yes. Use the direction toggle to switch to YAML → TOML mode. Top-level keys become [sections], nested objects use dotted keys or nested section headers, and YAML sequences of objects become TOML arrays of tables [[key]].

What TOML features are supported?

The parser supports tables, arrays of tables, inline tables, basic and literal strings, multiline strings, integers (including hex, octal, binary), floats, booleans, datetimes, and dotted keys. This covers all features used in most Cargo.toml and pyproject.toml files.

How are type differences handled between TOML and YAML?

Both formats support strings, integers, floats, and booleans, which map directly. TOML's datetime types become YAML strings since YAML has no native datetime type. YAML's yes/no/on/off boolean synonyms are converted to TOML's strict true/false. Null values in YAML are omitted in TOML output since TOML has no null type.

Is my configuration data sent to any server?

No. All parsing and conversion runs entirely in your browser. Your TOML and YAML content never leave your device. No data is collected, stored, or transmitted to any server.

Real-world Examples

Cargo.toml to YAML for CI/CD

Convert a Rust Cargo.toml into YAML for use in a CI/CD pipeline configuration.

Input

[package]
name = "my-rust-app"
version = "0.1.0"
edition = "2021"

[dependencies]
serde = { version = "1.0", features = ["derive"] }
tokio = { version = "1", features = ["full"] }

[[bin]]
name = "my-app"
path = "src/main.rs"

[[bin]]
name = "cli-tool"
path = "src/cli.rs"

Output

package:
  name: my-rust-app
  version: 0.1.0
  edition: "2021"
dependencies:
  serde:
    version: "1.0"
    features:
      - derive
  tokio:
    version: "1"
    features:
      - full
bin:
  - name: my-app
    path: src/main.rs
  - name: cli-tool
    path: src/cli.rs

YAML Config to TOML for Python Tool

Convert a YAML application configuration into TOML format for a Python tool that requires pyproject.toml-style input.