Formatador YAML

Format and validate YAML documents

100% gratuito. Funciona totalmente no seu navegador: seus arquivos e dados nunca saem do seu dispositivo e nada é enviado para nenhum servidor.

YAML Input

Drop a YAML file, click to browse, or paste

YAML, YML · up to 5 MB · never uploaded

Formatted YAML
10Lines
5Top-level Keys
118Output chars

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Sobre esta ferramenta

YAML runs the modern deployment stack - Docker Compose, Kubernetes manifests, GitHub Actions, Ansible playbooks - and it has one characteristic that makes it uniquely error-prone: indentation carries meaning. In JSON, braces mark structure and whitespace is decoration. In YAML, moving a line two spaces changes which parent it belongs to, and the file may still parse perfectly while meaning something entirely different. That is the dangerous failure: not an error at deploy time, but a container that silently reads the wrong config. Tabs are the other classic trap - YAML forbids them for indentation, and an editor that inserts one produces an error whose message rarely says so plainly. There is also the "Norway problem", where unquoted no, yes, on and off are read as booleans rather than strings. Validating before committing catches all three. Parsing runs in your browser, so files containing credentials are never uploaded.

Como usar esta ferramenta

  1. Paste your YAMLA Compose file, Kubernetes manifest, workflow definition or any other config.
  2. Read the validation resultSyntax errors are reported with their position - usually an indentation problem or a stray tab.
  3. Check the formatted structureConsistent re-indentation makes the nesting visible, which is how you spot a key attached to the wrong parent.
  4. Copy it backTake the cleaned version into your repository.

Por que usar

  • Catches indentation and tab errors before they reach a pipeline or cluster.
  • Makes nesting visible, which is the only reliable way to spot a misplaced key.
  • Runs in your browser, so config files containing secrets and connection strings are never transmitted.
  • Handles multi-document files separated by ---.
  • No account and no size limit.

Usos comuns

  • Checking a Kubernetes manifest before applying it to a cluster.
  • Validating a GitHub Actions workflow without pushing a commit to test it.
  • Debugging a Docker Compose file that fails with an unhelpful parse error.
  • Reviewing a config file someone else edited by hand.
  • Cleaning up inconsistent indentation across a config directory.

Dicas para melhores resultados

  • Configure your editor to insert spaces, never tabs, in YAML files. This eliminates the single most common error permanently.
  • Quote strings that could be read as booleans - no, yes, on, off - and version numbers like 1.10, which otherwise become floats and lose the trailing zero.
  • Two spaces per level is the near-universal convention. Consistency matters more than the number.
  • Watch for a colon inside an unquoted value, which YAML reads as a new key-value pair.
  • If you need to convert between formats rather than clean up formatting, use the YAML ⇄ JSON converter.

Erros a evitar

  • Using tabs for indentation. YAML forbids it outright, and the resulting error message rarely says so clearly.
  • Mixing indentation widths within one file, which can silently reparent a block rather than failing.
  • Leaving version numbers unquoted, so 1.10 becomes the number 1.1 and the trailing zero disappears.
  • Leaving no unquoted in a country or option list, where YAML converts it to the boolean false.
  • Assuming a file that parses is correct. Valid YAML can still be the wrong shape for the system reading it.

Perguntas frequentes

Paste it above. Syntax is checked immediately and any error is reported with its position, alongside a consistently indented version that makes the structure readable.

Yes. No account, no size limit and nothing uploaded.

Because indentation defines structure rather than braces. Changing a line's indentation changes which parent it belongs to, and the file can still be valid YAML while meaning something completely different - which is why the failure often appears at runtime rather than at parse time.

YAML does not permit tabs for indentation at all. Set your editor to insert spaces in .yml and .yaml files and the problem disappears for good.

Because unquoted, YAML reads it as a floating-point number, and 1.10 equals 1.1. Quote version numbers as strings - "1.10" - to preserve them exactly.

Unquoted no, yes, on and off are interpreted as booleans, so a list of country codes containing NO becomes false. Quoting the values prevents it.

It validates syntax and structure. It cannot know whether a field name is valid for Kubernetes or GitHub Actions - that requires validation against those systems' own schemas.

No. Parsing happens in your browser, which is important because config files routinely contain connection strings, tokens and other secrets.

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