Convert YAML to JSON and JSON back to YAML, both ways. Validates as it converts and shows clear errors. Everything runs in your browser.
How to use the YAML ⇄ JSON
Choose the direction: YAML to JSON or JSON to YAML.
Paste your YAML or JSON into the input panel.
Copy the converted result, or read the error if the input is invalid.
This converter transforms YAML into JSON and JSON into YAML, in both directions. Pick the direction, paste your input, and copy the converted result or read a clear error if the input is malformed.
Everything is processed locally in your browser, so your data stays on your device.
YAML and JSON describe the same kind of data, but with different priorities. JSON is strict and compact, which suits APIs and machines; YAML is indentation-based and easier for people to read and edit, which is why it dominates configuration files.
Each conversion parses the source first, so malformed input is caught and reported with the reason and often the line, instead of silently producing a broken result. A successful conversion therefore also tells you the input was valid.
It uses the YAML 1.2 and 1.1 compatible parser from js-yaml, covering the features you meet in practice: mappings, sequences, scalars, anchors and multi-line strings.
This is exactly the glue you need around CI pipelines, Kubernetes and Docker Compose files, and APIs that speak JSON while your config is written in YAML. It lets you move between the two without hand-editing.
One thing to know: YAML comments are dropped, because JSON has no concept of comments, and converting back generates fresh YAML without them.
Frequently asked questions
It uses the YAML 1.2 / 1.1 compatible parser from js-yaml, covering the common features: mappings, sequences, scalars, anchors and multi-line strings.
The input is parsed before converting, so invalid YAML or JSON shows a message with the reason and often the line, which helps you spot the problem quickly.
No. YAML comments are dropped during conversion because JSON has no comments, and converting back generates fresh YAML without them.
No. The conversion runs entirely in your browser; nothing you paste leaves your device.
Many tools and APIs require JSON, while YAML is friendlier to write and read for configuration. Converting lets you keep human-friendly config and still feed JSON to the systems that need it.
Embed this tool
Add this tool to your own website. Copy the snippet below; it stays up to date automatically.
<iframe src="https://monu.tools/embed/en/yaml-json-converter" width="100%" height="640" style="border:1px solid #e5e5e5;border-radius:12px;max-width:680px" loading="lazy" title="Monu Tools"></iframe>Learn more
YAML vs JSON: Which One Should Your Config Use?
YAML vs JSON compared for config files and APIs: syntax, comments, the Norway problem, indentation traps, TOML, and lossless conversion.
Why Is My JSON Invalid? How to Find and Fix the Error
The six mistakes that break JSON, how to read a parser error, and how to fix invalid JSON fast.
How to Minify JSON to Shrink API Payloads
What minifying JSON actually removes, the realistic 20 to 40 percent size win, and why server compression usually matters more.
How to Convert JSON to CSV (and Keep Nested Data Sane)
Convert JSON to CSV without losing your nested objects: flattening, exploding arrays, delimiters, Excel BOM gotchas, and the round-trip back.
Turn a JSON Response into a TypeScript Interface in Seconds
Generate a TypeScript interface from any JSON response: optional fields, nullables, nested types, and where a single sample falls short.
Related tools
Format, beautify and validate JSON online with clear error messages for invalid input.
Minify and validate JSON in your browser, and see how many bytes you save.
Convert JSON to CSV and CSV back to JSON, both ways. Choose the delimiter, handle quoted fields, and copy the result. Everything runs in your browser.
Generate TypeScript interfaces from a JSON sample, with nested types, arrays and optional fields. Runs in your browser.