JSON vs YAML: which data format should you use?
Verdict: JSON wins for data exchange — every API and language parses it natively, and its strict brackets leave no room for ambiguity. YAML wins for human-written configuration — cleaner to read, with comments. Payloads and APIs go JSON; hand-edited config goes YAML.
| Criterion | JSON | YAML |
|---|---|---|
| Primary use | APIs and data interchange | Config files (CI, Kubernetes, apps) |
| Readability | Noisy brackets and quotes | Clean, minimal, indentation-based |
| Comments | Not allowed by the standard | Supported with # |
| Parsing | Built into every language | Needs a YAML library |
| Strictness | Strict and unambiguous | Forgiving, but indentation errors bite |
| Best for | Machine-to-machine data | Human-maintained configuration |
Use JSON when
- Sending data between services or to a browser
- You need parsing in any language with zero dependencies
- Strict, unambiguous structure matters more than brevity
- Storing nested data that config files would mangle
Use YAML when
- Humans will read and edit the file regularly
- You need comments explaining settings
- Writing CI pipelines or deployment manifests
- Brevity and scannability beat strictness
Convert for free, privately
Every tool below runs entirely in your browser — your files never leave your device.
Frequently asked questions
Can JSON have comments?
Standard JSON forbids comments, which is why config often moves to YAML or JSONC/JSON5. If your tooling accepts JSONC, that is a middle ground — otherwise convert to YAML.
Is YAML a superset of JSON?
Effectively yes — valid JSON parses as YAML 1.2 in most parsers. That makes JSON-to-YAML conversion safe and mechanical.
Why do YAML files break so often?
Almost always tabs-for-indentation or a stray colon in an unquoted string. Use spaces only, quote strings containing colons or leading special characters, and validate after editing.
Can I convert between JSON and YAML without pasting secrets into a site?
Yes — the linked converters run entirely in your browser, so API keys and config values never leave your device.