Free JSON to YAML Converter (and YAML to JSON)
Paste JSON or YAML and convert in either direction — handy for Kubernetes manifests, CI configs, and API payloads. Runs in your browser.
Why so much DevOps tooling settled on YAML
Kubernetes manifests, GitHub Actions workflows, Docker Compose files, and Ansible playbooks are all written in YAML rather than JSON — despite YAML being, formally, a superset of JSON's data model. The appeal is that YAML's indentation-based block style is far more pleasant to hand-write and review in a diff than JSON's mandatory braces, brackets, and commas on every line. The tradeoff is that YAML's indentation is meaningful, not cosmetic — mixing tabs and spaces, or getting a nested list's indentation level wrong, silently changes what the document means (or breaks parsing outright), which is exactly the class of error the FAQ below addresses.
What doesn't survive a JSON → YAML → JSON round trip
Comments are the one thing this conversion can never add automatically: JSON has no syntax for comments, so there's nothing for the converter to preserve when generating YAML from JSON input. Add any # comments you want directly in the YAML output afterward — they simply won't be there yet coming from a JSON source.
Frequently Asked Questions
Is every JSON document valid YAML?
Yes — YAML is a superset of JSON, so any valid JSON already parses as YAML. Converting to YAML rewrites it in the indented block style people usually mean by "YAML", which is easier to read and edit.
Does the converter preserve data types?
Yes. Numbers, booleans, nulls, strings, arrays, and nested objects convert faithfully in both directions. Strings that look like numbers or booleans are quoted in the YAML output so they stay strings.
Why did my YAML fail to convert?
The most common causes are inconsistent indentation (tabs are not allowed in YAML — use spaces) and unquoted special characters like colons inside values. The error message shows the line where parsing failed.
Why do Kubernetes, GitHub Actions, and Docker Compose all use YAML?
YAML's indentation-based block style is easier to hand-write and review in a code diff than JSON's braces and commas, which matters a lot for config files that engineers edit directly and frequently. The cost is that indentation actually means something in YAML, unlike JSON, so a misaligned line can silently change the document's structure.
Will converting JSON to YAML add comments for me?
No — JSON has no comment syntax at all, so there's nothing for the converter to carry over. Any # comments in the YAML output have to be added by hand after conversion.
Is my configuration data uploaded?
No. Conversion runs entirely in your browser using a local YAML library — safe for configs containing internal hostnames or settings. Never paste secrets or credentials into any web tool, including this one.