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42 lines
1.4 KiB
Markdown
42 lines
1.4 KiB
Markdown
# Precedence Of Dot Env Files
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_Dot Env_ files like `.env`, `.env.development`, `.env.local`, etc. are one of
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the main ways to configure your Next.js app across various environments.
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It's not uncommon to see several different `.env*` files in production app that
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is under active development.
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Here is an example of almost every variant in play:
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```bash
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$ ls -a -1 .env*
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.env
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.env.development
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.env.development.local
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.env.development.local.example
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.env.local
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.env.production
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.env.test
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```
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So, how does Next.js decide which files to load and in what order?
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It will always attempt to load `.env` and `.env.local` (except in `test`) if
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those exist. It will also look for environment-specific files based on the
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`NODE_ENV` (which can be one of `development`, `test`, or `production`). So, in
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`development`, the `.env.development` and `.env.development.local` will be
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loaded. Something like `.env.development.local.example` isn't on the list, but
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rather is a convention for a dotenv file's template.
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As for the order, the environment itself (your system's environment variables)
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which are present in `process.env` take the highest precedence. After that, it
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looks in any of the follow present files in this order, stopping once it finds
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what it is looking for:
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- `.env.$(NODE_ENV).local`
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- `.env.local`
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- `.env.$(NODE_ENV)`
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- `.env`
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[source](https://nextjs.org/docs/pages/building-your-application/configuring/environment-variables#environment-variable-load-order)
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