Multi-Environment .env Generator

Every real application ends up with environment-specific values: a local database URL, a staging API key, a production log level. The clean pattern is a base .env plus small per-environment files — .env.dev, .env.staging, .env.prod — but generating those by copying and hand-editing guarantees drift, and drift is what breaks a deploy at 2am.

The Multi-Environment .env Generator scaffolds the whole set in one click. Paste your base .env, add override sections marked [dev], [staging] and [prod], and the tool emits each environment's complete file — base plus its own overrides — with a summary of what changed per environment. The environment list itself is editable, so preview or qa work the same way.

The result is deterministic and diffable: the differences between environments are exactly the overrides you wrote, nothing more. And everything happens in your browser.

• Base + overrides: one file to edit, many environments emitted.
• Section syntax: [dev], [staging], [prod] blocks in one textarea.
• Editable env list: any comma-separated environment names.
• Per-env summary: shows which keys each environment overrides.
• Key validation: valid .env keys; bad lines flagged.
• Clean values: quotes unwrapped, consistent output.
• Copy or download: copy all, or download each .env file.
• Private: all conversion happens in your browser.

1. Paste the base .env into the first box, or load the sample.
2. Add override sections in the second box using [dev] / [staging] / [prod] headers.
3. Adjust the environment list if you need custom names.
4. Click Generate. Every environment file appears in the result box.
5. Review the per-env summaries, then copy each or download them.

Example 1 — Standard three-env app. A backend team scaffolds dev, staging and production from one base; the only differences are the DATABASE_URL and log level, which read cleanly from the overrides.

Example 2 — Review environments. An agency adds review to the environment list so every PR preview gets its own .env with a unique DATABASE_URL.

Example 3 — Security-conscious releases. A fintech team keeps prod credentials only in the [prod] section, so the base and dev files contain no secrets at all.

Example 4 — Frontend feature flags. A frontend squad overrides FEATURE_* flags per environment to test rollouts before they reach production.

Example 5 — Onboarding. New developers generate their local .env.dev from the committed base in seconds and start coding without hunting for values.

• One source, many files: overrides are the only differences.
• Reviewable: per-env summaries make changes obvious.
• No secrets by default: keep prod values isolated to [prod].
• Deterministic: same base and overrides, same files.
• Flexible: any environment names supported.
• Private & free: browser-only, no account.