What does it do?
It converts a .env file to JSON and JSON to .env, following the same rules as dotenv: export prefixes, comments, single quotes (literal), double quotes (with \n escapes and values over several lines) and inline comments after unquoted values.
While converting, it reports what loaders usually accept in silence:
- Duplicate keys, with the line of the first definition.
- Unclosed quotes and stray quotes in the middle of a value.
- Spaces around =, which break
docker run --env-file and shells.
- Unquoted values with spaces and invalid variable names.
Options
- Numbers and booleans:
PORT=3000 becomes 3000 instead of "3000".
- Nest KEY__SUB: builds nested objects from double underscores.
- UPPER_CASE keys (JSON to .env):
apiUrl becomes APIURL; nested keys are joined with __.
Frequently asked questions
›Is my .env stored or sent anywhere?
No. This tool is marked as sensitive: the content is not saved in your browser, cannot be shared by link and never leaves the page.
›Which value wins when a key is repeated?
The last one, as in dotenv, Docker Compose and most loaders. The tool warns you because the first definition is usually a leftover that someone will edit by mistake.
›What does nesting with __ do?
It turns DB__HOST and DB__PORT into { DB: { HOST, PORT } }, the convention used by ASP.NET Core and many config libraries. JSON to .env does the opposite: nested objects are flattened with __.