YAML Validator

Validate YAML syntax and convert between YAML and JSON.

Mode

Input

Output

Lines: 0

Keys: 0

Common YAML Gotchas

Gotcha	Example	Problem	Fix
Norway Problem	country: NO	Parsed as boolean false	country: "NO" or country: 'NO'
Colon in string	url: http://example.com	May break parsing	url: "http://example.com"
Tab indentation	Using tabs	YAML forbids tabs	Use spaces only (2 is standard)
Trailing spaces	key: value	Can cause subtle issues	Trim trailing whitespace
Multi-line strings	Long values	Confusing syntax	Use \| for literal, > for folded
Anchors abuse	Complex &/*refs	Hard to debug	Keep anchors simple or avoid them
Numeric strings	version: 1.0	Parsed as float, not string	version: "1.0"
Yes/No values	flag: yes	Parsed as boolean true	flag: "yes" if you want string

How to Use This Validator

Paste your YAML

Or load a sample template

See validation results

Instant syntax checking with error details

Convert if needed

Switch between YAML and JSON formats

The #1 YAML Mistake: The Norway Problem

NO, yes, off, on are all parsed as booleans in YAML 1.1. Always quote strings that could be misinterpreted. YAML 1.2 fixed this, but many parsers still use 1.1 rules.