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

Name: YAML to dotenv
Availability: InStock
Author: Nham Vu

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

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

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: 2026-07-26 · Reviewed by Nham Vu