Convert YAML to JSON

Paste your YAML into the input panel or upload a .yaml/.yml file, then click Convert. The JSON appears in the right panel ready to copy or download. Everything runs in your browser, so nothing is uploaded to a server.

Yes. YAML files that separate documents with --- are fully supported, which is common in Kubernetes manifests. A single document converts to a JSON object, and a multi-document file converts to a JSON array with one entry per document, keeping the original order.

Yes. YAML anchors (&name) and aliases (*name) are expanded before conversion, so the JSON output contains the full value everywhere the alias was used. Merge keys (<<:) are also applied, which matters for Docker Compose and CI configuration files that share common blocks.

This converter follows the YAML 1.2 core schema, where only true and false are booleans. Older YAML 1.1 parsers also treated yes, no, on and off as booleans, which is the source of the famous Norway problem where the country code NO turned into false. Keeping them as strings is the modern, safer behaviour. Our guide on what gets lost when you convert YAML to JSON has the full side-by-side table — under YAML 1.1, 012 becomes 10 and 12:30 becomes 750.

YAML timestamps are converted to ISO 8601 strings, because JSON has no native date type. YAML also allows .inf and .nan, which JSON cannot represent at all — if your file contains them the tool warns you instead of silently writing null.

You can upload YAML files up to 100MB. All conversion happens entirely in your browser — your data is never sent to any server.