YAML and TOML are both human-readable config formats, but serve different use cases. The 5 key differences:
[section] headers.yes/no to booleans.Configuration files define how your software behaves in every environment. YAML and TOML have become the dominant formats for modern developer tooling: Kubernetes uses YAML, Rust's Cargo uses TOML, and Python packaging has adopted TOML in pyproject.toml. This guide covers what you need to know about both formats, their common pitfalls, and how to move data between them.
YAML (YAML Ain't Markup Language) uses indentation to represent hierarchy — there are no braces or brackets. This makes it clean to read but notoriously sensitive to whitespace errors.
Indentation rules: YAML uses spaces only — never tabs. The number of spaces must be consistent within a document (2 or 4 spaces per level are standard). A single tab character anywhere in a YAML file causes a parse error.
Key-value pairs: Written as key: value with a mandatory space after the colon. Missing the space (key:value) is a common error.
Strings: Most strings don't need quotes. You need quotes when the value contains special characters or could be misinterpreted as a boolean. YAML 1.1 treats yes, no, true, false, on, off as booleans.
Multi-document YAML: Use --- to separate multiple documents in a single file — common in Kubernetes manifests that define multiple resources.
Tab characters — The most common and hardest to spot. Configure your editor to show whitespace characters and enforce spaces-only for YAML files.
Inconsistent indentation — Mixing 2-space and 4-space indentation in the same file causes silent structural errors. Use our YAML Formatter to normalise indentation in one click.
Implicit type coercion — YAML 1.1 treats yes/no/on/off as booleans and bare numbers as integers or floats. A port value of 0800 gets parsed as octal 512. Always quote ambiguous values.
Anchor and alias errors — YAML anchors (&name) and aliases (*name) are powerful but confusing. Our YAML to JSON Converter resolves anchors and shows the fully expanded result.
TOML (Tom's Obvious Minimal Language) was designed specifically for configuration files that humans edit directly. Unlike YAML, TOML is unambiguous — there is no indentation to miscount and no implicit type coercion.
Key sections: TOML uses [section] headers instead of indentation. A Cargo.toml file has sections like [package], [dependencies], and [dev-dependencies].
Array of tables: The [[table]] syntax creates an array of objects — used for things like multiple binary targets in Cargo.toml.
Types: TOML is strongly typed. It distinguishes integers, floats, booleans, strings, datetime, arrays, and inline tables. There is no implicit coercion — port = 8080 is always an integer.
Comments: Unlike JSON, TOML supports comments with #. This makes it ideal for configuration files where you want to explain each setting inline.
Use YAML when the tooling requires it (Kubernetes, Helm, Ansible, most CI/CD systems), when you need comments and anchors, or when the config is primarily written and read by machines.
Use TOML when humans edit the file directly and correctness matters more than compactness. Rust's Cargo.toml, Python's pyproject.toml, and Hugo's config.toml are canonical examples.
Use JSON when the config is consumed by JavaScript/Node.js code (package.json, tsconfig.json), or when you need the simplest possible format with maximum parser support.
Converting between these formats is straightforward: our JSON to YAML, JSON to TOML, YAML to JSON, and TOML to JSON converters handle the translation in your browser.
A causa mais comum é a indentação com tabulação em vez de espaços. Alguns editores inserem tabulações silenciosamente. Passe seu YAML pelo nosso Formatador YAML para normalizar os espaços em branco antes de fazer o commit.
Sim. O YAML suporta comentários com #. Tudo, do # até o fim da linha, é ignorado — uma das principais vantagens do YAML sobre o JSON para arquivos de configuração.
O TOML v1.0 (lançado em 2021) esclareceu casos extremos envolvendo strings de várias linhas, nomes de chave Unicode e formatos de data e hora. A maioria das ferramentas modernas (Cargo 1.54+, o tomllib do Python) usa a v1.0. Nosso formatador é compatível com a v1.0.
Use nosso Conversor de YAML para JSON. Cole seu manifesto e clique em Converter. A saída é um JSON válido que o kubectl e a maioria dos clientes Kubernetes aceitam.
A comunidade de empacotamento do Python escolheu o TOML porque ele suporta comentários (ao contrário do JSON), é inequívoco (ao contrário dos tipos implícitos do YAML) e é amigável para humanos. A PEP 518 (2016) especificou o TOML para essa finalidade.