.env to Docker Compose Converter

Docker Compose is one of the most common homes for environment configuration, and its environment: section follows YAML rules that are full of foot-guns. A value that starts with a # becomes a comment. A 8080 handed as a string arrives as a number. A REGION=eu-west-1 full of colons can fail to parse. And hand-transcribing a .env of forty variables is precisely where a production value gets silently corrupted.

The .env to Docker Compose Converter turns your .env into a correct compose environment block in one click. Choose a top-level environment: map, or nest it under services.<name>.environment for the service you are configuring. Types are preserved automatically, quoting is applied only where YAML needs it (with a force-quote toggle), and quoted values from the .env are unwrapped and cleaned before output.

It is a strict, deterministic transform: the same .env always yields the same block, so switching compose branches and environments stays reproducible. Everything runs locally — nothing leaves your browser.

• Two placements: a top-level environment: map or services.<name>.environment.
• Smart YAML quoting: values are quoted only when YAML parsing would change them.
• Type preservation: numbers, booleans and null stay unquoted (toggleable).
• Force-quote: optionally quote every value as a string.
• Quoted .env handling: double- and single-wrapped values are unwrapped correctly.
• Full key support: keys with dots, dashes and underscores pass through untouched.
• Duplicate detection: repeated keys are reported with line numbers.
• Source header: optional comment noting the block came from a .env file.
• Copy or download: clipboard or a .yml file in one click.
• Private: all conversion happens in your browser.

1. Paste your .env content into the input box, or load the sample to see quoting, types and comments in action.
2. Choose the placement. Leave Service name empty for a top-level environment: block, or type a service name like web.
3. Tune the options. Preserve types, force single-quoting, and add a source header comment.
4. Click Convert. The compose YAML appears on the right.
5. Review warnings such as duplicate keys above the output.
6. Copy or download the block and paste it into your docker-compose.yml.

Example 1 — Standalone API container. A developer converts DATABASE_URL, PORT and DEBUG into a top-level environment block and drops it under their api service; the colons and slashes in the URL stay intact thanks to automatic quoting.

Example 2 — Multi-service compose. An engineer converts a full .env once and targets different service names per dependency, producing a clean services block where each service gets only its own variables.

Example 3 — Feature flags with types. A team keeps FEATURE_X=true and MAX_RETRIES=5 in a .env; with type preservation they reach the container as real booleans and numbers, so feature-flag libraries work without string parsing.

Example 4 — CI templating. A pipeline exports secrets to a temp .env, converts it to a compose block and writes docker-compose.yml automatically — no manual transcription, no quoting mistakes.

Example 5 — Local development parity. A dev converts the same .env used by their local runner into compose format, keeping development and containerized environments identical.

• Valid YAML: quoting rules are handled, so compose parses every time.
• Exact values: the container sees exactly what the .env contains.
• Real types: numbers, booleans and null are preserved natively.
• Flexible placement: top-level or per-service output.
• Deterministic: same input, same output, easy to script and test.
• Private & free: browser-only, instant, no account.