What YAML structures are supported?

Both flat and nested mappings work. Nested keys are flattened into an underscore-joined, uppercase environment variable name, for example database: { host: localhost } becomes DATABASE_HOST=localhost.

How are nested keys turned into environment variable names?

Each level of nesting is uppercased, non-alphanumeric characters become underscores, and levels are joined with an underscore. app.database.port becomes APP_DATABASE_PORT.

What happens to YAML arrays?

Arrays of plain values (strings, numbers, booleans) are joined into a single comma-separated line, like ALLOWED_HOSTS=localhost,127.0.0.1. Arrays that contain nested objects are skipped and listed as a warning, since dotenv has no way to represent them.

Are values with spaces or special characters handled correctly?

Yes. Any string value containing spaces, quotes, or other shell-special characters is automatically wrapped in double quotes in the output.

What if two different YAML keys flatten to the same environment variable name?

This can happen, for example db-host and db_host both become DB_HOST. The tool warns you about the collision and keeps both lines, but only the last one takes effect when the file is loaded.

Is my data sent to a server?

No. All parsing and conversion happens entirely in your browser using the js-yaml library. Nothing is transmitted or stored outside your device.

Can I convert JSON to .env instead?

This tool is for YAML input. For flat JSON objects, use the JSON to .env converter tool.

YAML to dotenv

Paste YAML config and instantly get flattened .env KEY=VALUE lines, with nested keys joined by underscores.

YAML Input

.env Output

Nested keys flatten

Nested mappings become underscore-joined, uppercase env var names.

100% client-side

Your data never leaves the browser. Safe for secrets and API keys.

Auto-quoted values

Strings with spaces or special characters are wrapped in double quotes automatically.

Summary

This tool converts a YAML configuration file into .env (dotenv) format. Flat keys map directly to KEY=VALUE lines, and nested mapping keys are flattened into a single UPPER_SNAKE_CASE name joined by underscores. Arrays of plain values are joined into one comma-separated line. The conversion runs entirely in your browser, so secrets never leave your device.

How it works

Paste or type your YAML configuration into the input panel.
The tool parses the YAML client-side using the js-yaml library.
Nested mapping keys are flattened into UPPER_SNAKE_CASE names joined by underscores, so database.host becomes DATABASE_HOST.
Arrays of plain values are joined into a single comma-separated line; arrays containing objects are skipped with a warning.
String values with spaces or special characters are wrapped in double quotes automatically.
Click "Copy" or "Download" to grab the resulting .env file.

Use cases

Convert a nested YAML config, such as a Kubernetes ConfigMap or app.yaml file, into a .env file for local development.
Generate environment variable definitions from a YAML secrets export.
Prepare .env files for Docker, CI/CD pipelines, or serverless functions from an existing YAML config.
Flatten nested YAML sections into prefixed environment variable names without hand-editing.
Migrate a Helm values.yaml file into environment variables for a container.
Preview how a YAML config would look once flattened, before committing a .env file to a repository.

Frequently Asked Questions

Last updated: 2026-09-09 · Reviewed by Nham Vu

YAML to dotenv

Use the YAML to dotenv

Summary

How it works

Use cases

Frequently Asked Questions