YAML Tools

YAML Formatter & Beautifier

Normalize any YAML to clean, consistent style — uniform indentation, canonical quoting, validation built in.

In short

Format YAML online: normalize indentation (2/3/4 spaces), clean up quoting, validate with exact error positions. Ideal for K8s and CI files. Free.

By NaveenKumar T · Updated 17 Sep 2026

Learn: TOML vs YAML vs JSON: Choosing a Configuration Format

2/3/4-space indentation
Canonical smart quoting
Validates while formatting

Runs entirely in your browser — nothing you paste or open here is uploaded, logged, or stored.How we handle data →

Example

YAML Formatter: input and output

A short release-notes header written with a mix of double quotes, single quotes and a flow-style list — three notations for the same kind of data.

Input · yaml

title: "Release Notes"
version: '1.4.2'
tags: [stable, "lts"]
published: true
authors:
  - name: Grace Hopper
    role: "Maintainer"
  - name: Ada Lovelace
    role: Contributor

Output · yaml

title: Release Notes
version: 1.4.2
tags:
  - stable
  - lts
published: true
authors:
  - name: Grace Hopper
    role: Maintainer
  - name: Ada Lovelace
    role: Contributor

Every unnecessary quote disappears — "Release Notes", '1.4.2' and "lts" all come back unquoted — and the flow-style tags: [stable, "lts"] list is rewritten as a block list. The data underneath is identical; only the notation changes.

Learn more

What formatting YAML actually does

Unlike JSON formatting (pure whitespace), YAML formatting is re-serialization: the document is parsed to its data and written back in canonical style. That's what makes it powerful — mixed 2-and-4-space files come out uniform, exotic quoting collapses to the minimal correct form, and flow-style fragments ({a: 1}) become consistent block style.

It also makes the formatter a strict validator: anything that formats successfully is guaranteed-parseable YAML 1.2, with errors located to the exact character when it isn't.

House style for YAML

Two-space indentation is the de-facto standard across Kubernetes, GitHub Actions, and almost every modern tool — use it unless your team has standardized otherwise. Run files through the formatter before committing and diffs stop arguing about style; reviews see only real changes.

Help

Frequently asked questions

Everything you need to know about the YAML Formatter.

01How do I use the YAML Formatter?

Paste your YAML, choose an indent width, and press Format. The document is parsed and re-serialized in clean, consistent style — uniform indents, quoting only where required — ready to copy or download.

02Will formatting change my YAML's meaning?

The DATA never changes — the document re-serializes to identical values. Style normalizes: inconsistent indents become uniform, unnecessary quotes are dropped (and necessary ones added), and anchors/aliases are expanded to their values. Comments, which exist outside the data model, are not preserved through re-serialization.

03Why does the formatter refuse to format broken YAML instead of doing its best?

Because 'doing its best' with whitespace-significant syntax means guessing which parent a mis-indented key actually belongs to — exactly the kind of silent misinterpretation YAML is prone to. Formatting requires a successful full parse first, so a document that can't be formatted is reported with the exact line and column of the problem instead of being reformatted around a guess that might attach a value to the wrong block.

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