What is this tool?

This YAML validator checks whether your text is syntactically valid YAML in real time. It shows a Valid or Invalid badge in the editor toolbar, lists parse issues with line and column hints when available, and keeps everything in your browser. Use it before committing configs, pasting into CI, or applying manifests to a cluster.

Why use a dedicated YAML validator?

IDEs validate YAML, but a browser tool is handy when you are reviewing a snippet from chat, a ticket, or a log. This page focuses on syntax and structure—not Kubernetes schema rules (those need cluster-specific tools). Pair it with the YAML Formatter when you want pretty-print or minify after the file parses cleanly.

• Catch indentation and mapping errors before kubectl apply or pipeline runs
• Share or save validated documents with built-in Share / Save (same document model as other Spoold tools)
• Copy YAML quickly from the toolbar; load a sample to see a valid baseline

Key features

• Live validation — Debounced parse as you type
• Issue list — Compact panel under the editor when YAML is invalid
• Share & Save — Local or cloud saves with optional share links
• History & Saved — Reopen recent or saved YAML
• Syntax highlighting — Monaco editor with YAML mode
• Privacy-first — Validation runs client-side; optional cloud save is explicit

How it works

1. Paste or type YAML — The toolbar shows byte size and status.
2. Read the badge — Valid means the parser accepted the document; Invalid opens the issue list.
3. Fix errors — Use line/col hints to jump in your editor.
4. Format when ready — Open the formatter to normalize indentation or minify.

Use cases

Best practices

• Validate then format — Fix Invalid YAML first; then use the formatter for style.
• Use spaces consistently — Tabs mixed with spaces often cause confusing errors.
• Quote ambiguous scalars — Booleans and timestamps can be misread if left unquoted.
• Do not paste secrets on shared machines — Even client-side tools cannot prevent shoulder surfing.

Common errors

• Bad indentation — Nested keys must align under their parent.
• Broken sequences — List items under a key need consistent dash indentation.
• Duplicate keys — Valid YAML may still surprise you at runtime if keys repeat.
• Invisible characters — Copy-paste from PDFs or slides can insert bad bytes; retype or paste via plain text.

FAQ

Related terms

Search intent includes YAML validator, YAML validator online, validate YAML, YAML syntax checker, YAML lint online, YAML parse error, fix invalid YAML, check YAML syntax, YAML 1.2 validator, and free YAML checker.

Infra and DevOps: Kubernetes YAML validate, GitHub Actions YAML check, docker compose yaml syntax, Ansible playbook yaml lint, Helm values yaml validate, OpenAPI yaml validator, CloudFormation yaml syntax check, and client-side yaml tool.

Nearby tools: YAML formatter, JSON formatter, JSON to YAML, TOML formatter, XML formatter, and code minifier for YAML compaction workflows.

Similar tools

Explore related utilities:

• YAML Formatter
• YAML Diff
• JSON ↔ YAML
• JSON Formatter
• TOML Formatter
• XML Formatter

Conclusion

A fast online YAML validator reduces surprises from malformed configs. This tool combines live parsing, clear Valid/Invalid feedback, optional Share and Save, and history—all aligned with the rest of the Spoold toolbox. When syntax is clean, switch to the YAML Formatter for indentation and minify.