Are my comments preserved?

No. JSON has no comment syntax, so comments are discarded when converting to YAML's output. Converting JSON to YAML cannot invent them either. If a config file's comments matter, keep the YAML as the source of truth and treat the JSON as a derived artifact.

Which YAML features are supported?

Nested mappings and sequences, inline flow style, quoted and unquoted scalars, multi-line block scalars with the pipe and greater-than indicators, explicit nulls, booleans, numbers, and comments. Anchors, aliases, merge keys, custom tags and multiple documents in one file are not supported, and the tool tells you rather than guessing.

Does this run on a server?

No. The conversion happens in your browser, so configuration files that contain hostnames, internal service names or secrets are never transmitted. Nothing is stored between visits either.

Why did my unquoted value change type?

YAML infers types from unquoted text, so no becomes false, 08 may be read as a number, and 1.20 becomes 1.2. If you need a value to stay a string, wrap it in quotes. Seeing this happen in the JSON output is one of the more useful side effects of converting.

Encoding & conversion

YAML to JSON Converter (and Back)

Convert between YAML and JSON in either direction.

Direction

YAML input

YAML to convert

JSON output

About this tool

YAML and JSON describe the same data model, so anything expressible in one can be expressed in the other. They differ only in surface syntax: JSON uses braces and quotes, YAML uses indentation and is far easier to write by hand and to comment.

Converting between them comes up constantly once you work with infrastructure. Kubernetes manifests, GitHub Actions workflows, Docker Compose files and OpenAPI specs are conventionally YAML, while most APIs, test fixtures and programmatic tooling expect JSON. Going YAML to JSON is usually about feeding a config file into something that only speaks JSON. Going the other way is usually about turning a generated payload into something a human will be editing and reviewing.

The conversion is also a quick way to check that YAML means what you think it means. YAML has some famously surprising corners: an unquoted yes or no becomes a boolean, a leading zero can make a number octal, and a value like 1.20 loses its trailing zero. Seeing the JSON equivalent shows you the actual parsed types rather than the characters you typed, which is often how a configuration bug gets spotted.

Comments are worth knowing about in advance. YAML supports them and JSON does not, so comments are dropped when converting to JSON. There is nowhere for them to go, and a round trip through JSON will not bring them back.

How to use it

Choose a direction: YAML to JSON, or JSON to YAML.
Paste your document into the input panel.
Read the converted output, or the error panel if the input could not be parsed.
Copy the result.

Frequently asked questions

Are my comments preserved?: No. JSON has no comment syntax, so comments are discarded when converting to YAML's output. Converting JSON to YAML cannot invent them either. If a config file's comments matter, keep the YAML as the source of truth and treat the JSON as a derived artifact.
Which YAML features are supported?: Nested mappings and sequences, inline flow style, quoted and unquoted scalars, multi-line block scalars with the pipe and greater-than indicators, explicit nulls, booleans, numbers, and comments. Anchors, aliases, merge keys, custom tags and multiple documents in one file are not supported, and the tool tells you rather than guessing.
Does this run on a server?: No. The conversion happens in your browser, so configuration files that contain hostnames, internal service names or secrets are never transmitted. Nothing is stored between visits either.
Why did my unquoted value change type?: YAML infers types from unquoted text, so no becomes false, 08 may be read as a number, and 1.20 becomes 1.2. If you need a value to stay a string, wrap it in quotes. Seeing this happen in the JSON output is one of the more useful side effects of converting.