Laravel Localization: Managing Language Files, Setting Locale, and Using Translation Strings

Introduction

Laravel provides a simple folder‑based approach for localization, allowing applications to support multiple languages. Language files are stored in the resources/lang directory, with each language having its own sub‑folder (e.g., en , es ).

/resources
    /lang
        /en
            messages.php
        /es
            messages.php

Each language file returns an associative array of key‑value pairs, for example:

'Welcome to our application'
];
?>

Locale Settings

The default locale is defined in config/app.php . You can change the current locale at runtime using the App facade's setLocale method:

Route::get('welcome/{locale}', function ($locale) {
    App::setLocale($locale);
    //
});

A fallback locale can also be configured in config/app.php :

'fallback_locale' => 'en',

Determine Current Locale

You can retrieve the current locale with App::getLocale() and check it with App::isLocale('en') :

$locale = App::getLocale();
if (App::isLocale('en')) {
    //
}

Defining Translation Strings

Using Short Keys

Translation files under resources/lang contain arrays of short keys:

/resources
    /lang
        /en
            messages.php
        /es
            messages.php

'Welcome to our application'
];
?>

Using Translation Strings as Keys

For large projects you can store full text keys in JSON files, e.g., resources/lang/es.json :

{
    "I love programming.": "Me encanta programar."
}

Retrieving Translation Strings

The __ helper fetches translations. It accepts the file and key as the first argument:

echo __('messages.welcome');
echo __('I love programming.');

In Blade templates you can use {{ __() }} or the @lang directive:

{{ __('messages.welcome') }}
@lang('messages.welcome')

If a translation key does not exist, __ simply returns the key name.

Parameter Replacement in Translation Strings

Placeholders prefixed with : can be defined in translation strings and replaced by passing an associative array to __ :

'welcome' => 'Welcome, :name',

echo __('messages.welcome', ['name' => 'dayle']);

Upper‑case placeholders preserve case in the output.

Pluralization

Plural forms are defined using the pipe | separator or more complex range rules:

'apples' => 'There is one apple|There are many apples',

'apples' => '{0} There are none|[1,19] There are some|[20,*] There are many',

Use trans_choice to retrieve the appropriate string based on a quantity, optionally replacing placeholders:

echo trans_choice('messages.apples', 10);

'minutes_ago' => '{1} :value minute ago|[2,*] :value minutes ago',

echo trans_choice('time.minutes_ago', 5, ['value' => 5]);