YAML Formatter

How to use YAML Formatter

1. Open YAML Formatter — it runs entirely in your browser with no setup.
2. Paste or type your input into the text area, or upload a file where supported.
3. Set any options you need. The result appears in the output panel — there is no upload step and no waiting on a server.
4. Review the output instantly; large inputs are handled locally without lag.
5. Copy the result to your clipboard or download it. Your data never leaves the page.

Why use YAML Formatter?

• 100% free with no limits, no sign-up and no watermarks.
• Private by design — your data are processed in your browser and never uploaded to a server.
• Fast and lightweight, with instant results even on a phone or a slow connection.
• Works everywhere — any modern browser on Windows, macOS, Linux, Android or iOS.
• Part of a full developer tools suite, so related yaml formatter tasks are one click away.

What people use YAML Formatter for

• Fixing the indentation of a CI, Kubernetes or Docker Compose file that will not parse.
• Finding out which line is actually causing a YAML syntax error.
• Normalising a config file assembled from several snippets.

YAML Formatter: limits and things worth knowing

• Tabs are illegal in YAML indentation. This is the single most common cause of an unparseable file, and it is invisible in most editors — a tab pasted in from documentation looks identical to spaces.
• Indentation is structural, not cosmetic. Changing it changes the document, which is why re-indenting YAML by hand is risky and worth doing with a parser instead.
• Unquoted no, off, yes and on are read as booleans under YAML 1.1, which is what makes a country code of NO become false. Quote any value you mean as a string.
• A colon followed by a space inside an unquoted value splits the line into a key and a value. URLs and Windows paths usually need quoting for this reason.

Is it private and secure?

Your privacy is built in. YAML Formatter runs completely on your device, so whatever you enter stays in your browser and is never transmitted, logged or stored on any server.

Network activity: none. Nothing is sent and nothing is fetched. This tool makes no network request at all once the page has loaded — which is why it keeps working if your connection drops.

You do not have to take that on trust — our privacy proof page publishes the Content-Security-Policy that enforces it, lists every third party it permits, and shows how to verify the whole claim yourself.

Learn more

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