Why convert YAML to JSON?
YAML and JSON describe the same data shapes - maps, lists, and scalars - but they target different audiences. YAML is friendlier to humans editing config files. JSON is the format every API, every JavaScript runtime, and every database driver speaks natively. Converting between the two is a routine task when you are debugging an OpenAPI spec, diffing a Kubernetes manifest, or pasting config into a tool that only accepts JSON.
What the converter handles
- Anchors and aliases -
&nameand*namereferences are expanded. - Merge keys -
<<: *defaultsis resolved by merging the referenced map into the current map. - Multiline strings - literal (
|) and folded (>) block scalars become regular JSON strings with the correct newline characters. - Tagged values - explicit
!!strand!!inttags are resolved to the underlying scalar type. - Booleans and null -
yes,true,onbecometrue;no,false,offbecomefalse;~andnullbecomenull.
What does not survive the round-trip
JSON has no syntax for comments, no anchors, and no support for multiple documents in a single file. If your YAML uses these features, they are lost during conversion. To preserve documentation, move the comments into a dedicated description field before converting.
FAQs
How do I convert YAML to JSON?
Paste your YAML in the left panel and the equivalent JSON appears on the right instantly. Choose 2 or 4 space indentation, then copy the JSON to your clipboard or download it as a .json file.
Does the converter support YAML anchors and aliases?
Yes. YAML anchors (&name), aliases (*name), and merge keys (<<:) are resolved during conversion, so the JSON output contains the fully expanded structure.
What happens to YAML comments during conversion?
JSON has no comment syntax, so YAML comments (#) are dropped. If you need to preserve documentation, move comments into a description field or a separate readme.
How are multiline strings handled?
Block scalars - literal (|) and folded (>) - are converted to JSON strings with the correct newline characters. Chomping indicators (-, +) are respected, so trailing newlines behave exactly as the YAML 1.2 spec defines.
Can I convert YAML files larger than a few hundred KB?
Yes. The converter handles up to 5 MB per request, which covers nearly every real-world Kubernetes manifest, OpenAPI spec, or Compose file. For larger payloads, split the YAML into multiple documents.
Is my YAML sent to a server?
No. YAML parsing and JSON generation happen in your browser, so your data never leaves your device. The tool is safe for secrets, internal config, and proprietary infrastructure files.
How does YAML to JSON conversion handle dates?
YAML date scalars like 2026-04-28 are converted to ISO 8601 strings in JSON. JSON has no native date type, so applications must parse the string back if they need a Date object.
Can I convert multi-document YAML files?
The converter parses the first document. To convert each document separately, split your file at the --- separators and run them through the converter one at a time.
Why does my YAML to JSON conversion fail?
The converter shows the exact line and column of the syntax error. The most common causes are inconsistent indentation, missing colons, duplicate keys, or unquoted strings that contain reserved characters.
How do I convert YML to JSON?
YML and YAML are the same format - the .yml extension is just a shorter alias for .yaml. Use this converter exactly the same way regardless of which extension your file uses.