Convert common block-style YAML to JSON without sending the text anywhere. This tool supports a deliberately limited subset and reports unsupported YAML features instead of silently interpreting them as something else.
YAML to JSON converter
Use spaces for indentation. Limits: 50,000 characters, 2,000 non-empty lines, and 200 indentation spaces. The supported subset and rejected forms are listed below.
Choose Convert to parse the sample.
What YAML does this converter accept?
It accepts indentation-based block mappings and sequences, quoted or plain scalar keys and values, comments, and JSON-style flow arrays or objects. It recognizes null, ~, booleans, and simple decimal numbers; other plain scalars remain strings. Mapping keys must be unique.
For predictable results, use spaces rather than tabs and put a space after a mapping colon. The parser rejects YAML document markers and directives, anchors, aliases, tags, block scalars, explicit keys, YAML-style flow collections, duplicate keys, and constructs outside this subset. Integer values outside JavaScript's exact integer range are rejected so their digits are not silently changed. A rejection means the input needs a different YAML parser; it does not prove the document is invalid YAML.
YAML has more syntax and scalar-resolution rules than this small converter implements. Check the linked YAML 1.2.2 specification when interpreting documents that depend on those rules.
Frequently asked questions
Does this accept every YAML document?
No. It supports a subset of block mappings and sequences, plus JSON-style flow values. Anchors, aliases, tags, block scalars, YAML flow collections, directives, and other unsupported forms are rejected.
How are plain values typed?
The converter recognizes null, true, false, and simple decimal numbers. Other plain values are kept as strings. Unsafe large integers are rejected to avoid changing digits. This limited rule is not full YAML 1.2.2 schema resolution.
Is my YAML uploaded?
No. Parsing and conversion run in this page. The tool does not fetch remote data or store the pasted text.
What demand evidence supports this tool?
Ahrefs' July 16, 2026 article lists 2,900 monthly searches for “yaml to json.” The article does not explicitly label the country scope; this third-party metric is not this site's traffic or a forecast.
Sources · checked November 5, 2026
Related: convert CSV to JSON, format JSON, and compare JSON responses.
Methodology and limitations
This local converter accepts indentation-based block mappings and sequences, quoted and plain scalar keys and values, and JSON-style flow arrays and objects. It recognizes null, booleans, and simple decimal numbers; other plain scalars remain strings. It rejects tabs for indentation, duplicate keys, anchors, aliases, tags, YAML flow syntax, directives, document separators, and block scalars rather than guessing. Limits are 50,000 characters, 2,000 non-empty lines, and 200 indentation spaces. Integers outside JavaScript's exact integer range are rejected to avoid silently changing their digits. Its supported subset is intentionally smaller than YAML 1.2.2. Ahrefs' July 16, 2026 free-tools article lists monthly search volume 2,900 for “yaml to json”; the article does not explicitly identify the volume's country scope. Observed November 5, 2026; this third-party estimate is not this site's traffic or a forecast.
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