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Kenji Tomita
Kenji Tomita

Posted on • Edited on

Understanding Laravel's .env Caching and How to Avoid Common Pitfalls

#laravel

When developing locally with Laravel, you might encounter these frustrating problems:

  • You change the .env file, but the changes don't take effect
  • Your app unexpectedly connects to the wrong environment (database, API, etc.)
  • Configuration values seem stale and outdated

Most often, these issues are caused by configuration caching.

How .env and Configuration Caching Work

Laravel uses environment variables defined in .env inside its config files under config/*.php. To improve performance, especially in production, Laravel allows you to cache all your configuration and environment variables into a single file.

Running php artisan optimize creates this cache.
Specifically, config::cache compiles .env values into bootstrap/cache/config.php, so changes to .env won't be picked up until the cache is cleared.

Location and Contents of Cache Files

Configuration caches are stored in the bootstrap/cache/ directory.
After running php artisan optimize, you'll typically see files like:

bootstrap/cache/config.php     ← configuration cache
bootstrap/cache/routes-v7.php  ← route cache
bootstrap/cache/packages.php   ← package cache
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Opening config.php reveals an array with all .env values expanded and saved.
As long as this cache exists, Laravel won't reload your .env file directly.

How to Avoid Cache Issues

If you want .env changes to apply immediately, clear the cache:

php artisan config:clear
php artisan cache:clear
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A Tool I Built to Check .env vs Cache Differences

I personally got stuck many times wondering "Why am I connecting to the wrong environment?" To help, I created a CLI tool that easily compares your .env file and the cached config.php to highlight differences.

👉 tommykw/laravel-env-diff

Note on Artisan Commands and Current Limitations

I wasn't aware that custom Artisan commands could be created, so I implemented this tool as a standalone Rust CLI.

Also, there are some cases that the current implementation does not yet cover, including:

  • Environment variable expansion (e.g., MAIL_FROM_NAME="${APP_NAME}")
  • Values present in $_ENV but not in the .env file
  • .env.[environment] files for environment-specific configuration
  • Non-local file systems

How to Install 

git clone git@github.com:tommykw/laravel-env-diff.git
cd laravel-env-diff
cargo build --release
cargo install --path .
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How to Run

After installation, run the tool from the root directory of your Laravel project:

laravel-env-diff
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Sample Output 

=== Differences between .env and bootstrap/cache/config.php ===
[DIFF] DB_HOST
[DIFF] REDIS_PASSWORD
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This output shows which environment variable keys differ between your .env and the cached config.
It helps you quickly identify what hasn't been reflected in the cache.

Summary

  • .env values get cached into bootstrap/cache/config.php by config:cache
  • If .env changes don't take effect, clear the cache with artisan commands

Understanding .env caching saves you a lot of debugging time.

Top comments (2)

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xwero profile image
david duymelinck •

I don't understand why you created it in Rust instead as an artisan command? it probably is faster but If you want to run it on a production server the Rust dependency can be a hurdle.

There are also a few cases I can think of that are not met by the current code;

  • An .env value can be an environment value MAIL_FROM_NAME="${APP_NAME}"
  • The env function reads the (dotEnv library extended) $_ENV variable, this means the key doesn't need to be in the .env file
  • Laravel has the option to use .env.[environment] files to specify values in different environments.
  • The file system is not always local .
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tommykw profile image
Kenji Tomita •

Thank you for your comment.
I actually didn’t know that you could create custom Artisan commands.
As you mentioned, implementing it as an Artisan command would be better.
Also, I missed supporting the cases you pointed out.