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Yasser Elgammal
Yasser Elgammal

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How Laravel Loads and Caches Translation Files in Localization

#laravel #php #programming

Localization is one of Laravel's powerful features, allowing developers to support multiple languages seamlessly using either PHP array files or JSON files.

But one question that often comes up is:

Does Laravel cache translations? And how does it handle large translation files?

Let’s break it down and understand what actually happens under the hood.

Laravel Supports Two Types of Translation Files

1️⃣ PHP Array Files

Located in:
/lang/{locale}/messages.php

Structure:

return [
    'welcome' => 'Welcome to our website',
    'login'   => 'Login here',
];
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Usage:

__('messages.welcome')
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2️⃣ JSON Files

Located in:
/lang/{locale}.json

Structure:

{
    "Welcome": "Welcome to our website",
    "Login": "Login here"
}
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Usage:

__('Welcome')
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When Does Laravel Load Translation Files?

Laravel does not load all translation files at once.

Instead:

  • It loads a translation file only when a key is requested from it.
  • Then it stores the entire file content in memory (an internal PHP array) for the rest of the current request.

This behavior is implemented inside the Illuminate\Translation\FileLoader and Translator classes.

Internally, Laravel stores loaded translations in a private property like $loaded, and avoids loading the same file twice during one request.

What Is Runtime Cache?

Runtime cache means that Laravel keeps the translations in memory only during the current HTTP request.

If you call:

__('messages.welcome')
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Multiple times during the same request, Laravel will:

  • Load the file once via require.
  • Reuse the cached values in memory for any further translation calls.

This boosts performance by avoiding redundant file reads.

Once the request ends, this cache is discarded.

Laravel Does NOT Persist Translation Cache

Unlike routes, config, or compiled views, Laravel does not cache translations to disk.

There is no php artisan translations:cache command, and no bootstrap/cache storage for translations.

Why?

Because translation files are often small, and caching them permanently can:

  • Complicated dynamic multilingual updates.
  • Increase risk of stale data if edited manually.

What About Large Translation Files?

Laravel loads the full translation file when a key is requested.

That means:

  • If your messages.php file has 2000 keys, all of them will be loaded into memory when you use any one of them.
  • This can have memory implications in huge apps.

Best Practice:
Organize your translations into smaller, modular files like:

  • auth.php
  • dashboard.php
  • messages.php

Then reference them as:

__('dashboard.title')
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Quick Recap

  • Laravel supports both PHP arrays and JSON translation formats.
  • Translation files are loaded only when a key is requested.
  • Laravel uses in-memory cache for the duration of a single request.
  • There is no persistent disk caching for translations.
  • Split large translation files into smaller files to improve maintainability and memory efficiency.

Thanks for reading!

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References

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Ahmed Niazy •

Greeeet