JSON/YAML
Convert, validate, and format JSON and YAML data with ease
JSON Input
YAML Output
JSON/YAML Tool Features:
- Convert: Seamlessly convert between JSON and YAML formats
- Validate: Check syntax and structure of your data
- Format: Pretty-print or minify your JSON/YAML data
- Sample Data: Use built-in samples to test functionality
About the JSON/YAML Tool
JSON and YAML express the same data structures — objects, arrays, strings, numbers, booleans and null — with very different syntax. JSON is compact and unambiguous, which makes it ideal for APIs and machine-to-machine exchange. YAML is indentation-based and supports comments, which makes it pleasant to read and write by hand in configuration files.
This tool converts between the two, validates a document against its syntax, and reformats or minifies it.
How to use it
- 1Choose a tab: convert, validate, or format.
- 2Paste your document, or upload a .json or .yaml file.
- 3Run the operation. Conversion produces the equivalent document in the other syntax; validation reports whether the document parses and where it fails if not; formatting re-indents or minifies.
- 4Copy the result, or download it as a file for larger documents.
When you would use it
- Converting a Kubernetes, Ansible or Docker Compose manifest between YAML and JSON.
- Formatting a minified API response so the nested structure is actually readable.
- Validating a configuration file before you commit it, with a line number when it is wrong.
How it works, and what it does not do
Parsing uses js-yaml for YAML and the platform JSON parser for JSON, so a malformed document reports where parsing stopped rather than failing silently or returning a half-converted result. Conversion itself is structural: the data is preserved exactly, but the original formatting, key order and comments are not.
The practical pitfall is indentation. YAML is whitespace-sensitive and does not permit tab characters for indentation, so a file can look perfectly aligned and still be invalid. When a document is rejected, the reported position is usually just above the real mistake — a value that needs quoting, or a colon inside an unquoted string.
Frequently asked questions
Why did my YAML fail to validate?
YAML is whitespace-sensitive, so the usual culprits are mixed tabs and spaces, inconsistent indentation between sibling keys, or a missing space after a colon. The validator reports the line where parsing stopped, which is normally the line just after the real mistake.
Are comments preserved when converting?
No. JSON has no comment syntax, so comments cannot survive a round-trip through JSON. If your YAML relies on comments, treat the YAML file as the source of truth and convert only when a consumer requires JSON.
Is JSON faster to parse than YAML?
Yes, generally. JSON parsers are simpler and most languages have highly optimised implementations. YAML parsing involves more work and has surprising edge cases, which is why JSON is preferred for high-volume data exchange and YAML for human-edited configuration.
What does minifying do?
It removes all insignificant whitespace — indentation, newlines and padding spaces — producing the smallest valid representation. Minified JSON is good for network transfer and unreadable for humans, so keep a formatted copy for editing.
Can it handle very large documents?
Files up to 100 MB are accepted and processed in memory. Above that, formatting or validating text you paste is usually quicker than an upload — and a configuration file that large is usually better generated by a script than edited by hand.
Should I write configuration in JSON or YAML?
YAML reads better for hand-edited configuration because it supports comments and avoids quoting every key. JSON is safer to generate programmatically: it has no indentation rules, no ambiguous scalar types, and every parser agrees on it.