Paste YAML to get 2-space-indented JSON. Anchors resolve into copies, implicit types apply, and comments drop because JSON has no comment syntax. Unquoted no can become false; quote values that must stay strings. Multi-document files with --- separators must be split first. Conversion stays in this tab.
Runs in this tab · nothing is uploaded · Verify in 10 seconds →
YAML → JSON parses the document (anchors resolved into copies, implicit types applied), and re-emits it as 2-space-indented JSON. Because YAML 1.2's data model is a superset of JSON's, every single-document YAML with standard types converts; comments are dropped, since JSON has no syntax for them.
YAML's terseness is measurable: converting all 26 documents of our sample corpus (parsed and re-emitted with the same yaml library this page uses), the pretty-printed JSON output was larger than its YAML equivalent by a median 45.3% (min 32.9%, max 78.6%), JSON pays for braces, quotes and commas that YAML's indentation replaces. The trade goes the other way at parse time, where JSON parsers are dramatically faster.
“Invalid YAML: …” quotes the parser's first complaint, most often a tab used for indentation (YAML forbids tabs) or inconsistent indent depth. If conversion succeeds but a value has the wrong type (no became false, 01234 became a number) that is YAML's implicit typing working as specified: quote the value in the YAML source and convert again. Multi-document files (--- separators) must be split first.
Convert when a tool only accepts JSON, when you want to audit what YAML's type guessing actually produced, or when you need configs in a canonical diffable form.
This page is a focused view of theJSON ↔ YAML Converter, which has the full set of options.
Single-document YAML with standard types, yes, YAML 1.2's data model is a superset of JSON's. Multi-document files (--- separators) must be split first, and exotic tags have no JSON equivalent.
YAML's implicit typing: unquoted no, yes, on, off parse as booleans in many parsers, and 007 becomes the number 7. Quote values in the YAML source when they must stay strings, converting to JSON is a quick way to audit for exactly these surprises.
They are resolved during parsing: every alias is replaced by a copy of the anchored value, so the JSON output contains the expanded data.