jsonc2yaml

Convert JSONC (JSON with // and /* */ comments) to clean YAML — preserving comments as # comments.

• Block-style YAML, 2-space indent, minimal key quoting
• // line comments and /* */ block comments are carried over
• // inside string values (e.g. URLs) is handled correctly
• Works as a CLI or a library

Install

npm install -g jsonc2yaml   # CLI
# or
npm install jsonc2yaml      # library

CLI

jsonc2yaml config.jsonc                 # YAML to stdout
jsonc2yaml config.jsonc -o config.yaml  # write to a file
cat config.jsonc | jsonc2yaml           # read from stdin

Library

import { jsoncToYaml } from 'jsonc2yaml';
import { readFileSync } from 'node:fs';

const yaml = jsoncToYaml(readFileSync('config.jsonc', 'utf8'));

Notes

• Leading comments become # lines above the key; same-line comments stay as trailing # comments.
• A standalone comment after the last item in a block is attached as a trailing comment on the container (YAML has no slot for it otherwise).
• Multi-line /* */ comments used as inline trailers are collapsed to one line.
• The underlying JSONC parser is lenient and recovers from some malformed input, so this is not a strict validator.

License

ISC