YAML Viewer — Free Online YAML Tree Viewer & Beautifier

YAML Viewer — Free Online YAML Tree Viewer & Beautifier. Free online YAML viewer: paste or open a .yaml/.yml file to beautify it, browse it as a collapsible tree, catch syntax errors by line and column and count keys — all in your browser.

Our free online YAML viewer turns messy configuration files into clean, readable YAML in real time.

Paste a Kubernetes manifest, a Docker Compose file, a GitHub Actions workflow, an Ansible playbook or an OpenAPI spec — or open a local .yaml / .yml file — and switch between a formatted view and an interactive YAML tree viewer that you can expand and collapse node by node.

Each branch shows how many items it contains (for example ports [2] for a two-item list), so even deeply nested configs are quick to navigate. The viewer doubles as a YAML beautifier and YAML syntax checker.

Invalid input is flagged immediately with the exact line and column of the first error (bad indentation, unclosed brackets, duplicate keys), while valid YAML is re-indented with 1–10 spaces, optionally sorted by key and rewritten with plain, single or double string quotes.

Multi-document streams separated by --- are kept intact, anchors and aliases stay valid, and a stats bar counts documents, keys, nesting depth and lines. Note that comments are not kept in the formatted output. Need a different format?

Use the YAML to JSON Converter, JSON to YAML Converter or YAML to TOML. Everything runs locally in your browser: your infrastructure configs, secrets and internal settings are never uploaded to a server.

Copy or download the formatted result as a .yaml file, or share a link that restores your YAML and options. Working with JSON instead? Try the JSON Viewer or JSON Prettify.

FAQ

How do I open and view a YAML file online?

Click Open .yaml file to load a .yaml, .yml or .txt file, or paste the content into Your raw YAML. The tool checks the syntax, shows the formatted YAML and counts documents, keys, lines and the maximum depth.

How do I browse YAML as a tree?

Click Tree view to explore the data as a collapsible tree, and use Expand all or Collapse all to open or close every level. Click Formatted to go back to the prettified text. Files with several documents show each one separately.

How do I find a YAML syntax error?

If the YAML is invalid, a message shows the line and column with the parser's explanation, such as bad indentation or an unclosed quote. Valid input shows Valid YAML.

Why are my comments missing from the formatted YAML?

The formatted version is rebuilt from the parsed data, so comments are not kept and anchors and aliases are written out as their full values. Your original text in the input box is not changed.

Is my YAML uploaded to a server?

No. Parsing and formatting run in your browser. Your YAML and settings are remembered in this browser's local storage so they are still there next time; click Clear to remove the text.

How to use this online tool

YAML Viewer — Free Online YAML Tree Viewer & Beautifier is designed for fast browser workflows when you need to format, validate, convert, decode, encode, generate, or inspect data without opening a heavy desktop app. Start with the input field or visible options, review the result, then copy or download the output for the next step.

Private processing in your browser

YAML Viewer — Free Online YAML Tree Viewer & Beautifier keeps the normal processing step local in your browser. That is useful for code snippets, tokens, documents, configuration values, text samples, and other material that should not be sent to a remote service unless you explicitly choose to share it.

When this tool is useful

Use YAML Viewer — Free Online YAML Tree Viewer & Beautifier for repeatable developer tasks, technical documentation, QA checks, quick conversions, debugging, content cleanup, and internal team workflows. The page focuses on clear inputs, immediate feedback, and output that is easy to reuse in code, reports, tickets, emails, or notes.

Practical tips

Before copying the final result, check important details such as spacing, casing, filenames, encoding, token structure, line breaks, or output format. Small checks prevent mistakes when the result is reused in source code, API requests, documentation, spreadsheets, or shared files.