YAML to JSON Converter
Paste your YAML below and get JSON instantly. The conversion happens entirely on your device — nothing is uploaded — so it's safe for private data and works offline once loaded.
Example: YAML → JSON
YAML in
name: CalcCafe
tools:
- json
- yaml
rating: 4.9
JSON out
{
"name": "CalcCafe",
"tools": [
"json",
"yaml"
],
"rating": 4.9
}How it works
The converter parses your YAML into an in-memory data structure, then serialises that structure as JSON. Because both steps run client-side in JavaScript, conversion is instant and your data never touches a network. The same engine powers every JSON / YAML / XML / CSV pairing, so results stay consistent across directions — you can round-trip YAML → JSON and back without surprises.
Tips for clean JSON
- Use the From / To selectors to switch formats, or the ⇄ button to reverse the conversion and reuse the output as input.
- Set the indent to match your project's style (2 or 4 spaces).
- Invalid input shows a clear error message pointing at the problem instead of failing silently.
Good to know
This YAML to JSON Converter turns human-friendly YAML — the indentation-based format used by Kubernetes manifests, GitHub Actions workflows, Docker Compose files, Ansible playbooks and countless app config files — into JSON, the format that REST APIs, JavaScript code and most databases actually consume. It is aimed at developers, DevOps engineers and anyone who keeps configuration in YAML but needs to hand the same data to tooling that only speaks JSON.
Reaping for this tool typically happens when you want to programmatically validate a config, paste settings into a tool that expects JSON, debug why an API rejects your payload, or simply inspect how YAML's implicit typing (unquoted numbers, booleans and nulls) resolves into explicit JSON values. Because everything runs in your browser with no upload, it is also a safe choice for configs that contain internal hostnames, environment names or other data you would not want to send to a remote server.
Read the JSON output as the literal, fully-resolved version of your YAML: keys become quoted strings, sequences become arrays, and scalars are coerced to their detected type — so rating: 4.9 becomes the number 4.9, while a value you intended as text but left unquoted (like version: 1.0) may surface as a number rather than the string you expected. If a value comes out with the wrong type, that is your signal to quote it in the source YAML.
A practical caveat: this converter handles one YAML document at a time. If your file contains multiple documents separated by ---, split them and convert each section individually. Also watch the indent setting and the ⇄ reverse button — you can round-trip YAML to JSON and back, which is a quick way to confirm your YAML parsed the way you meant it to.
Frequently asked questions
Why convert YAML to JSON?
Most APIs, JavaScript apps and databases consume JSON, not YAML. Converting your YAML config or data to JSON lets you feed it to code, validate it, or store it programmatically.
Does it support multi-document YAML?
This tool converts a single YAML document. For multi-document files (separated by ---), convert one document at a time.
Is my data uploaded anywhere?
No. The conversion runs entirely in your browser using JavaScript — your data never leaves your device and nothing is sent to a server.
Is this converter free?
Yes, completely free with no sign-up, and no limits. It even works offline once the page has loaded.
People also ask
Does converting YAML to JSON lose any data or comments?
Yes — YAML comments (lines starting with #) are dropped because JSON has no comment syntax. The actual keys, values and structure are preserved, but formatting, anchors expanded inline, and ordering nuances are normalized during conversion.
Why does a YAML value like 'yes' or 'on' become true in JSON?
YAML treats certain unquoted words such as yes, no, on, off, true and false as booleans. If you need them kept as text, wrap the value in quotes in your YAML so the parser reads it as a string.
Can I convert JSON back to YAML?
Yes. Use the From/To selectors or the reverse (⇄) button to switch direction, since the same engine powers both YAML to JSON and JSON to YAML conversions.
Is YAML always valid JSON or vice versa?
JSON is technically a subset of YAML, so most JSON parses as YAML, but the reverse is not true — YAML supports comments, anchors, multiple documents and unquoted strings that have no JSON equivalent and must be converted first.
What happens if my YAML has a syntax error like bad indentation?
The converter shows a clear error message pointing at the problem rather than producing partial output. YAML is whitespace-sensitive, so the most common cause is inconsistent indentation or mixing tabs with spaces.
How do I control whether the JSON output is 2-space or 4-space indented?
Use the indent setting in the tool to pick 2 or 4 spaces so the JSON matches your project's style. The indent only affects formatting, not the data itself.
Is it safe to convert sensitive config files with this tool?
The conversion runs entirely in your browser using JavaScript, so the data is not uploaded to any server and works offline once the page has loaded. As with any web tool, only use it on devices and browsers you trust.
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