YAML Prettify — Free YML Formatter & YAML Beautifier Online

YAML Prettify — Free YML Formatter & YAML Beautifier Online. Prettify YAML online for free: re-indent, sort keys and normalise quotes in any YAML or YML file, spot syntax errors by line and column and explore the result as a tree.

YAML prettify cleans up hand-edited or machine-generated YAML in one step.

Paste your config or open a .yml file and this free YML formatter re-indents every level consistently (1–10 spaces), removes irregular spacing, expands inline flow-style lists and maps into readable block style and can sort keys alphabetically — handy before code review or when diffing two versions of the same file.

It works as a quick YAML pretty print for Kubernetes manifests, Helm values, Docker Compose, CI pipelines and application settings.

The YAML beautifier validates as you type: if the input cannot be parsed you get the exact line and column of the first error, and duplicate keys are rejected.

Choose plain, single-quoted or double-quoted strings, keep multi-document streams separated by ---, and check the stats bar for document, key, depth and line counts. Switch to the tree view to explore the structure node by node.

Comments are dropped from the prettified output, so keep your original if you rely on them. To convert rather than format, use the YAML to JSON Converter or TOML to YAML.

Formatting happens entirely in your browser — nothing is uploaded — and you can copy the result, download it as a .yaml file or share a link that restores your input and options. For JSON data, see JSON Prettify and the JSON Viewer.

Frequently asked questions

How do I prettify or format a YAML file?

Paste your YAML into Your raw YAML or click Open .yaml file. The Prettified version of your YAML appears below; click Copy, or Download .yaml to save it as formatted.yaml.

How do I change the YAML indentation or sort keys?

Set Indent size from 1 to 10 spaces (2 by default) and turn on Sort keys to order the keys of every mapping alphabetically. Both settings are applied to the output instantly.

What does the String quotes option do?

It sets how string values are written: Plain (minimal) adds quotes only where YAML needs them, while Single quotes or Double quotes wraps string values in that style. Keys stay unquoted wherever possible.

Does the YAML formatter keep my comments?

No. The output is rebuilt from the parsed data, so comments are dropped and anchors and aliases are expanded into their full values. Keep your original file if you need the comments.

Can I format a file with several YAML documents?

Yes. Documents separated by --- are each formatted and joined again with --- separators, which is handy for Kubernetes manifests. Use Tree view to inspect each document separately.

Does YAML prettify also check the syntax?

Yes. Invalid YAML shows an error with the line and column, so you can fix indentation or quoting problems first. Valid input shows Valid YAML together with counts of documents, keys, lines and depth.

How to use this online tool

YAML Prettify — Free YML Formatter & YAML Beautifier Online 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 Prettify — Free YML Formatter & YAML Beautifier Online 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 Prettify — Free YML Formatter & YAML Beautifier Online 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.