Which formats are supported?

JSON, YAML (1.2), and TOML. Any of the three can be the input or output. The converter uses js-yaml for YAML and smol-toml for TOML — both battle-tested libraries.

Does it preserve comments?

No. JSON doesn't support comments, so converting YAML-with-comments or TOML-with-comments to JSON will strip them. Going between YAML and TOML also loses comments (structural reasons). For comment-preserving edits, edit in the source format directly.

Why does TOML output fail for some inputs?

TOML requires a top-level table (object). If your JSON/YAML starts with an array or a primitive, TOML can't represent that at the root. Wrap it in a key like {"data": [...]} .

Is my config sent anywhere?

No. Parsing and serialization happen entirely in your browser. Nothing leaves your device. Safe for sensitive configs, secrets, and internal infrastructure files.

Can it handle multi-document YAML?

Currently no — only the first document is parsed. For multi-doc YAML (separated by --- ), split and convert each document individually.

JSON ↔ YAML ↔ TOML Converter

Paste any config file — JSON, YAML, or TOML — and convert between all three formats. Auto-detects the source format. Handles nested objects, arrays, booleans, numbers, and dates. Handy for flipping between YAML for Kubernetes/GitHub Actions and JSON for APIs, or porting configs between tooling ecosystems. 100% client-side: nothing is uploaded.

Auto-detect input format

From:To:

Sample:

YAML input

JSON output

{
  "app": {
    "name": "myapp",
    "version": "1.0.0",
    "debug": true
  },
  "database": {
    "host": "localhost",
    "port": 5432,
    "replicas": [
      "db1",
      "db2",
      "db3"
    ]
  },
  "features": {
    "auth": true,
    "analytics": false
  }
}

Notes

• Everything runs in your browser. No upload.
• Auto-detect works for most inputs; toggle manually if needed.
• TOML output requires a top-level object (not an array).
• JSON can't represent YAML/TOML comments — comments are stripped.
• Use \u2194 swap to flip direction fast.
• Handles nested objects, arrays, booleans, numbers, dates.

Frequently Asked Questions

Which formats are supported?: JSON, YAML (1.2), and TOML. Any of the three can be the input or output. The converter uses js-yaml for YAML and smol-toml for TOML — both battle-tested libraries.
Does it preserve comments?: No. JSON doesn't support comments, so converting YAML-with-comments or TOML-with-comments to JSON will strip them. Going between YAML and TOML also loses comments (structural reasons). For comment-preserving edits, edit in the source format directly.
Why does TOML output fail for some inputs?: TOML requires a top-level table (object). If your JSON/YAML starts with an array or a primitive, TOML can't represent that at the root. Wrap it in a key like <code>{"data": [...]}</code>.
Is my config sent anywhere?: No. Parsing and serialization happen entirely in your browser. Nothing leaves your device. Safe for sensitive configs, secrets, and internal infrastructure files.
Can it handle multi-document YAML?: Currently no — only the first document is parsed. For multi-doc YAML (separated by <code>---</code>), split and convert each document individually.

Related Tools

Markdown Editor

Free online Markdown editor with live preview. Write and preview Markdown in real-time with GitHub Flavored Markdown support.

WYSIWYG Markdown Editor

Rich text WYSIWYG editor that outputs clean Markdown. Free online visual Markdown editor.

Markdown to HTML

Convert Markdown to clean HTML code instantly. Free online Markdown to HTML converter with copy and download options.

HTML to Markdown

Convert HTML to clean Markdown instantly. Free online HTML to Markdown converter. Paste HTML and get Markdown output.

About JSON ↔ YAML ↔ TOML Converter

Convert config files between JSON, YAML, and TOML instantly. Auto-detects input format. Zero upload, runs in your browser. Free, no signup. This tool runs entirely in your browser, so your content is not sent to a server. MarkdownMe provides free, fast, and reliable Markdown tools for developers, writers, and anyone who works with Markdown.