Free YAML ↔ JSON converter
Switch direction with one click, paste a config or API payload, and get formatted output. Parsing uses a modern YAML 1.2–compatible engine; nothing is uploaded or stored on a server.
How to use this tool
- 1
Open YAML / JSON converter
Use it for this task: YAML <-> JSON conversion, pretty-print, copy-ready output - 100% in-browser.
- 2
Paste or upload the source content
Put the original text or file in the input area, then choose the conversion or formatting options.
- 3
Copy or download the converted result
Check the preview first, then copy the output or download the generated file.
Quick facts
| Runs offline? | Yes — parsing runs fully in this tab using the `yaml` npm package in your browser. |
|---|---|
| YAML version? | The parser follows YAML 1.2–compatible rules (via the `yaml` library) — good for typical configs; exotic edge cases may differ from every offline CLI. |
| Comments & multiple documents? | Single-document flows work best. Comments in YAML are ignored when converted to JSON; for multiple YAML documents, split them manually first. |
| Privacy? | No network — your text never leaves the device for this tool. |
Top use cases
- YAML <-> JSON conversion, pretty-print, copy-ready output - 100% in-browser.
- Runs offline?: Yes — parsing runs fully in this tab using the `yaml` npm package in your browser.
- YAML version?: The parser follows YAML 1.2–compatible rules (via the `yaml` library) — good for typical configs; exotic edge cases may differ from every offline CLI.
- Comments & multiple documents?: Single-document flows work best. Comments in YAML are ignored when converted to JSON; for multiple YAML documents, split them manually first.
- Privacy?: No network — your text never leaves the device for this tool.
FAQ
When should I use YAML vs JSON?▾
YAML is often used for config files and Kubernetes because it is human-readable and supports comments. JSON is the lingua franca of web APIs. This tool helps you move between the two while formatting results.
Will anchors, tags, and custom types round-trip perfectly?▾
Round-trips go through JSON values: anything that cannot be represented in JSON (e.g. some YAML tags) will be lost or transformed. Use this for structurally compatible data.
Why is my huge file slow?▾
Very large pastes are parsed synchronously in the browser. For multi-megabyte files, consider a local CLI; for normal configs, this page should feel instant.
Is my data sent to Safe Local Tools servers?▾
No. The site is static; conversion runs in your browser. Clear the page or refresh to discard the text.
Can I use JSON with trailing commas?▾
Standard JSON.parse does not allow trailing commas. Remove them or fix the JSON before converting to YAML.
What about JSON5 or other supersets?▾
Only strict JSON (ECMA-404) is accepted in JSON → YAML mode. For JSON5 or other dialects, normalize to JSON first with another tool.