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YAML Tools

Format, validate, view and convert YAML configuration files such as Kubernetes manifests, Docker Compose files and CI pipelines.

.env to YAML Converter Convert .env files to YAML for Docker Compose, Kubernetes or CI configs, optionally nesting keys on a separator. Base64 to YAML Decode a Base64 string back to YAML with syntax highlighting. CSV to YAML Converter Convert CSV to YAML online for free. Clean, readable YAML with configurable indentation. Docker Run to Docker Compose Convert one or more docker run commands into a docker-compose.yml: ports, volumes, env, restart, networks, healthchecks and more. HTML Table to YAML Converter Convert HTML to YAML online for free. Clean, readable YAML with configurable indentation. JSON to YAML Converter Convert JSON to YAML online for free. Clean, readable YAML with configurable indentation. Properties to YAML Converter Convert Spring Boot application.properties to application.yml, nesting dotted keys into a clean YAML tree. SQL to YAML Converter Convert SQL to YAML online for free. Clean, readable YAML with configurable indentation. TOML Formatter Format TOML files online. Normalise spacing, tables and arrays of tables into clean, canonical TOML. TOML to YAML Converter Convert TOML configuration (Cargo.toml, pyproject.toml, config.toml) to readable YAML. TOML Validator Validate TOML files online against the TOML 1.0 spec. Find syntax errors by line and column and see the parsed data as JSON. XML to YAML Converter Convert XML to YAML online for free. Clean, readable YAML with configurable indentation. YAML Beautifier Clean up messy Kubernetes, Compose and CI YAML: consistent indentation and spacing, with comments and anchors kept as written. YAML Converter Convert YAML to JSON, XML, CSV, TOML or an HTML table in one place. Anchors, aliases and multi-document files supported. YAML Editor Edit YAML online with syntax highlighting, live validation and a tree preview. Format and download your file when done. YAML Formatter Format YAML online with consistent indentation while keeping comments. Validate syntax and see the exact line of any error. YAML Parser Parse YAML online and see the resulting data as JSON and a tree. Check types, anchors and multi-document files. YAML Pretty Print Pretty print YAML online and see the yq, PyYAML and js-yaml settings that give the same block style, key order and indent. YAML to Base64 Convert YAML to a Base64 string online. UTF-8 safe; paste text or upload a .yaml file. YAML to CSV Converter Convert YAML to CSV online for free. Nested data is flattened into columns. YAML to Excel Converter Convert YAML to Excel online for free. Download a real .xlsx workbook generated in your browser. YAML to JSON Converter Convert YAML to JSON online for free. Get formatted JSON with types detected automatically. YAML to Properties Converter Convert application.yml / YAML into flat .properties key=value lines, with Spring-style [0] indexes for lists. YAML to TOML Converter Convert YAML to TOML with tables and arrays of tables — handy for Cargo, pyproject and Hugo configs. YAML to XML Converter Convert YAML to XML online for free. Attributes, arrays and root element are configurable. YAML URL Decode Decode a URL-encoded YAML string back into readable YAML. YAML URL Encode URL-encode YAML so it can be sent as a query-string parameter or form field without breaking the URL. YAML Validator Validate YAML syntax online. Catch bad indentation, duplicate keys and invalid values with exact line and column numbers. YAML Viewer View YAML as an interactive tree and table. Explore nested maps and lists and see how every value is parsed.

YAML tools for configuration you can trust

YAML is the configuration language of modern infrastructure: Kubernetes manifests, Docker Compose, GitHub Actions and GitLab CI pipelines, Ansible playbooks, OpenAPI specs and many application settings. It is pleasant to read, but indentation is significant and a few rules are surprising, so a misplaced space can silently change the meaning of a file. These YAML tools help you catch such problems before they reach production.

Which YAML tool fits your task?

  • Check a file for errors – the YAML validator reports syntax problems such as bad indentation, tabs or duplicate keys with their line numbers.
  • Normalize formatting – the YAML formatter re-indents consistently, which also makes diffs in code review cleaner.
  • Understand structure – the YAML viewer shows the parsed document as a tree, so you can see exactly what nests under what.
  • Convert for code or APIs – YAML to JSON shows how a parser interprets your file, and JSON to YAML turns API output into readable config.
  • Other formats – YAML to XML and YAML to CSV cover legacy and spreadsheet workflows, and CSV to YAML turns a table into structured config.
  • TOML files – the TOML validator helps with the related format used by Rust, Python packaging and Hugo.

A handy debugging workflow

When a deployment behaves strangely, convert the YAML to JSON. JSON has no implicit typing and no indentation rules, so it reveals the parser's view of the file: a value you expected to be the string "08" might have become a number, or a list item might have ended up under the wrong key because of indentation.

YAML, JSON or TOML?

All three describe nested data. JSON is strict and ideal for machine-to-machine exchange, YAML is the most readable for large human-edited configs, and TOML keeps things simple for small settings files with clear sections. Converters in this category let you move between them when a tool expects a different format than the one you have.

YAML gotchas worth knowing

  • Tabs are not allowed for indentation; use spaces only.
  • Implicit types – in YAML 1.1 parsers, yes, no, on and off become booleans, and a country code like NO can turn into false. Quote strings that could be misread.
  • Leading zeros and colons – 010 may be parsed as an octal number, and 12:30 as a base-60 number in older parsers. Quote them.
  • Multi-line strings – | keeps line breaks, > folds them into spaces.
  • Multiple documents in one file are separated by ---, common in Kubernetes manifests.

Your YAML is processed in the browser, so internal hostnames and settings are not uploaded. Still, remove real secrets before pasting configuration anywhere.

Frequently asked questions

Why does my YAML file fail to parse?
The most frequent causes are tabs used for indentation, inconsistent indentation levels, a missing space after a colon and unquoted special characters. The YAML validator shows the line where parsing failed.
Is YAML a superset of JSON?
YAML 1.2 is designed so that almost all JSON documents are valid YAML. That is why you can paste JSON into YAML tools and why converting between them is straightforward.
Why did my value turn into true or false?
Some YAML parsers treat words like yes, no, on and off as booleans. Put the value in quotes to keep it a string.
How do I check a Kubernetes or Docker Compose file?
Paste it into the YAML validator to catch syntax errors, then view it as a tree or convert it to JSON to confirm the structure. Schema checks for specific tools still need their own validators.