JSON to YAML converter
Convert JSON to YAML 1.2 that means exactly the same thing. Strings that YAML could misread, like "yes", "007" or "2026-10-09", are quoted automatically.
What you get
- Convert JSON to YAML online with quoting only where YAML needs it.
- Checked: the YAML is parsed back and compared with your JSON value by value, so nothing changes.
- Open a .json file or paste it: JSON to YML in one step, ready to copy or download as a .yaml file.
- Private and free: everything runs in your browser, nothing is uploaded, and there is no sign-up.
How each result is checked
- Your input is parsed with a strict, standards-compliant parser.
- The YAML output is parsed back with an independent YAML parser.
- The parsed-back data is compared with your original, value by value. Any difference is reported with its exact path.
What can't convert exactly
- Integers larger than 9,007,199,254,740,991 can lose precision when any JavaScript tool reads JSON. You get a warning when your input has one.
- Output follows YAML 1.2. Strings that YAML 1.1 readers (PyYAML, Ruby and other older libraries) would read as booleans, numbers or dates, such as yes, no, on, off, 1_000 or 2024-01-01, are quoted, so every YAML reader keeps them as strings.
- Numbers are written by value: 1.0 becomes 1 and 1e3 becomes 1000. The result names any number whose written form changes, because some readers (Python, for example) treat 1 and 1.0 differently.
Questions
Will "yes" or "007" change meaning in YAML?
No. Values that YAML could read as booleans, numbers or dates are quoted, and the round-trip check proves the data came back unchanged.
Is my data uploaded?
No. Conversion runs in your browser in a background worker. Nothing is sent to a server.
Is the YAML safe for Kubernetes, docker-compose and GitHub Actions?
Yes. Strings that YAML readers could take as booleans, numbers or dates (yes, no, on, 1_000, 2024-01-01) are quoted, so Kubernetes YAML, docker-compose files and workflows read the same values as your JSON. Copy the result or download it as a .yaml file.
How do I convert JSON to YAML online?
Paste your JSON or open a file on the left (or click Example). The YAML appears on the right as you type, already checked. Copy it, or download it as a file. Nothing is uploaded.
Can the YAML output be wrong?
Every result is checked before it is shown (the checks are listed on this page). If a check fails, the page says "Review needed" and why, instead of presenting the output as correct, and anything that cannot convert exactly is named in the notes.