YAML to JSON Converter
Quick answer
Paste any YAML document and read it as clean JSON instantly: anchors resolved, nested lists flattened into real arrays, indentation replaced with braces you can hand to any API. The converter runs on js-yaml in your browser, validates before converting, and never uploads your config anywhere.
Last updated: October 26, 2026
YAML is written for humans; JSON is consumed by machines. The conversion direction matters: you inherit a Kubernetes manifest, a GitHub Actions workflow or a Compose file and need the data inside it as JSON — for an API payload, a test fixture, a program that has no YAML parser. Because JSON is a subset of YAML 1.2, the conversion is lossless for everyday documents, but it is also revealing: anchors expand, quoting decisions become visible, and the implicit typing YAML does quietly (versions as floats, country codes as booleans) happens in the open. This converter does all of that client-side, so deployment files with tokens and internal hostnames never leave your tab.
Use the tool belowValid YAML, 480 B
name: codelive-studio
url: https://codelivestudio.cyou
price: 0
signup_required: false
privacy:
client_side: true
uploads: null
storage: browser-localStorage
tools:
- name: HTML/CSS/JS Playground
languages:
- html
- css
- javascript
live_preview: true
- name: JSON Formatter
features:
- beautify
- minify
- validate
- name: YAML Formatter
features:
- format
- validate
- convert
tags:
- free
- private
- no-signup
YAML to JSON Converter runs entirely in your browser, nothing you paste or type is uploaded to any server, and no account is needed.
Worked examples
Real input on the left, exactly what YAML to JSON Converter gives back on the right. Paste either side into the tool to re-create it.
1GitHub Actions job, anchors included
A typical workflow snippet with an anchor — exactly what you inherit from a team repo.
defaults: &defaults
runtime: node20
retries: 2
build:
<<: *defaults
steps:
- npm ci
- npm run build{
"defaults": {
"runtime": "node20",
"retries": 2
},
"build": {
"runtime": "node20",
"retries": 2,
"steps": [
"npm ci",
"npm run build"
]
}
}The &defaults anchor and *defaults alias are resolved into real repeated data, and the merge key << is flattened — the JSON is fully self-contained.
How do I convert YAML to JSON online?
- 1
Paste your YAML into the editor (or upload a .yaml file, or load the sample to see a realistic document with lists and nesting).
- 2
The parser validates while you type — a bad indent or missing colon reports js-yaml's real error with line and column before any conversion happens.
- 3
Switch the output pane to JSON: anchors are resolved, block lists become arrays and mappings become objects, formatted with clean indentation.
- 4
Copy the JSON or download it as a .json file. The reverse direction works on the same page — paste JSON, switch output to YAML.
What this YAML to JSON converter does well
Anchors and aliases resolved
YAML's &anchor and *alias deduplication is great for writing and terrible for machine reading. The converter resolves every alias into the actual repeated data, so the JSON you get is the complete, self-contained document with no references to chase.
Real error messages, not silent garbage
YAML's whitespace sensitivity means a tab in the wrong place silently changes meaning — or breaks parsing. You see js-yaml's genuine error with the exact line and column, so a broken manifest is diagnosed before it becomes a broken conversion.
Implicit typing made visible
YAML quietly turns on into true, 1.20 into 1.2 and country code no into false. The JSON output shows exactly what the parser decided — which is precisely the data your API will receive — so surprises surface here instead of in production.
Both directions, one tool
JSON back to YAML is the same page: paste JSON and switch the output pane. Round-tripping is also the fastest way to see what a clever YAML document actually means as plain data.
Private by architecture
Conversion happens in your browser tab with no upload endpoint. Kubernetes secrets, .env-style values and internal hostnames in pipeline configs stay on your machine — there is no account and no history anywhere.
Diff-friendly JSON output
Output is re-serialized from the parsed data with consistent indentation, so converting two versions of the same manifest produces JSON you can actually diff — no stray line-wrap decisions muddying the comparison.
Why YAML to JSON is the direction machines care about
Config lives in YAML because humans maintain it: comments explain the why, anchors de-duplicate repeated blocks, and indentation keeps four levels of nesting readable. But everything downstream of the config — CI APIs, cloud SDKs, test harnesses, scripting languages without a YAML library — consumes JSON. Converting YAML to JSON is the bridge step: the document stops being a file for editing and becomes data for processing.
The conversion is also an honest type-check. YAML's implicit typing is the source of the classic failures: the version number 1.20 arriving as 1.2, or a region code no becoming boolean false. When the JSON output shows you the parsed types explicitly, you can spot those landmines before an API call turns them into a four-hour debugging session. Wrap problematic values in quotes in the source, re-convert, and the types are correct end to end.
Multi-document YAML: the honest caveat
Kubernetes files routinely contain several YAML documents separated by --- lines. A JSON document has exactly one root, so a multi-doc file cannot map to a single JSON object. The converter parses the first document and reports clearly when more exist, rather than silently merging or dropping them — merge or split the file first depending on what your downstream tool expects.
Comments are the other loss. YAML comments have no JSON representation, so they are dropped during conversion — which is one more reason to keep the YAML as the editable source of truth and treat the JSON as a generated artifact, not the other way around.
Questions this tool answers
- yaml to json converter
- yaml to json
- convert yaml to json online
- yaml parser to json
- yaml to json online free
Frequently asked questions
Is YAML to JSON conversion lossless?
For the data, yes — JSON is a subset of YAML 1.2, so everyday documents convert exactly. Two things are inherently lost: comments (JSON has no comment syntax) and anchor/alias structure (the JSON contains the resolved data instead of the references). Values and types convert exactly as parsed.
Why did my version number change from 1.20 to 1.2?
That is YAML implicit typing, not a converter bug: an unquoted 1.20 is parsed as the float 1.2. The JSON shows you what the parser decided. Quote the value in the YAML (version: "1.20") and it converts as the string 1.20. The same rule explains on/off/yes/no turning into booleans.
Can it convert a multi-document YAML file?
A JSON document has a single root, so a file with several --- separated documents cannot become one JSON object. The converter parses the first document and tells you when others exist. Split the file or convert documents one at a time, then combine them as an array in JSON if your downstream tool accepts that.
Does the converter upload my Kubernetes manifests?
No. Parsing and conversion run in your browser with js-yaml loaded locally — there is no upload endpoint and no server-side copy. Secrets and internal hostnames in your configs stay on your device, and no account keeps a history of what you converted.
Can I convert JSON back to YAML?
Yes — the same tool does both directions. Paste JSON and switch the output pane to YAML to get canonical 2-space indentation with dash-style lists. Round-tripping is also a quick sanity check for what a YAML document actually means as data.
How do I validate my YAML before converting?
You already are: the converter validates with js-yaml as you type and reports syntax errors with line and column before converting anything. For formatting and indentation cleanup on the YAML side, the YAML formatter on this site uses the same parser.