If you're using Laravel 5.2 and you installed the auth related functionality with php artisan make:auth then your app/Http/routes.php file will include all auth-related routes by simply calling Route::auth().

The auth() method can be found in vendor/laravel/framework/src/Illuminate/Routing/Router.php. So if you want to do as some people suggest here and disable registration by removing unwanted routes (probably a good idea) then you have to copy the routes you still want from the auth() method and put them in app/Http/routes.php (replacing the call to Route::auth()). So for instance:

<?php
// This is app/Http/routes.php

// Authentication Routes...
Route::get('login', 'Auth\AuthController@showLoginForm');
Route::post('login', 'Auth\AuthController@login');
Route::get('logout', 'Auth\AuthController@logout');

// Registration Routes... removed!

// Password Reset Routes...
Route::get('password/reset/{token?}', 'Auth\PasswordController@showResetForm');
Route::post('password/email', 'Auth\PasswordController@sendResetLinkEmail');
Route::post('password/reset', 'Auth\PasswordController@reset');

If you're using lower version than 5.2 then it's probably different, I remember things changed quite a bit since 5.0, at some point artisan make:auth was even removed IIRC.

Method 1 for version 5.3

In laravel 5.3 don't have AuthController. to disable register route you should change in constructor of RegisterController like this:

You can change form:

public function __construct()
{

    $this->middleware('guest');

}

to:

public function __construct()
{

    Redirect::to('/')->send();

}

Note: for use Redirect don't forget to user Redirect; So user access to https://host_name/register it's redirect to "/".

Method 2 for version 5.3

When we use php artisan make:auth it's added Auth::route(); automatically. Please Override Route in /routes/web.php. You can change it's like this: * you need to comment this line: Auth::routes();

    <?php

/*
|--------------------------------------------------------------------------
| Web Routes
|--------------------------------------------------------------------------
|
| This file is where you may define all of the routes that are handled
| by your application. Just tell Laravel the URIs it should respond
| to using a Closure or controller method. Build something great!
|
*/


// Auth::routes();
Route::get('/login', 'Auth\LoginController@showLoginForm' );
Route::post('/login', 'Auth\LoginController@login');
Route::post('/logout', 'Auth\LoginController@logout');

Route::get('/home', 'HomeController@index');

Thanks! I hope it's can solve your problems.

For Laravel 5.3 and 5.4, here is the proper way to do it:

You have to change:

public function __construct()
    {
        $this->middleware('guest');
    }

to

public function __construct()
    {
        $this->middleware('auth');
    }

in app/Http/Controller/Auth/RegisterController.php

Overwriting the getRegister and postRegister is tricky - if you are using git there is a high possibility that .gitignore is set to ignore framework files which will lead to the outcome that registration will still be possible in your production environment (if laravel is installed via composer for example)

Another possibility is using routes.php and adding this line:

Route::any('/auth/register','HomeController@index');

This way the framework files are left alone and any request will still be redirected away from the Frameworks register module.

The AuthController.php @limonte has overwrite is in App\Http\Controllers\Auth, not in the vendor directory, so Git doesn't ignore this change.

I have added this functions:

public function register() {
    return redirect('/');
}

public function showRegistrationForm() {
    return redirect('/');
}

and it works correctly.

The following method works great:

Copy all the routes from /vendor/laravel/framework/src/Illuminate/Routing/Router.php and paste it into web.php and comment out or delete Auth::routes().

Then setup a conditional to enable and disable registration from .env. Duplicate the 503.blade.php file in views/errors and create a 403 forbidden or whatever you like.

Add ALLOW_USER_REGISTRATION= to .env and control user registration by setting its value to true or false.

Now you have full control of routes and Vendor files remain untouched.

web.php

//Auth::routes();

// Authentication Routes...
Route::get('login', 'Auth\LoginController@showLoginForm')->name('login');
Route::post('login', 'Auth\LoginController@login');
Route::post('logout', 'Auth\LoginController@logout')->name('logout');

// Registration Routes...
if (env('ALLOW_USER_REGISTRATION', true))
{
    Route::get('register', 'Auth\RegisterController@showRegistrationForm')->name('register');
    Route::post('register', 'Auth\RegisterController@register');
}
else
{
    Route::match(['get','post'], 'register', function () {
        return view('errors.403');
    })->name('register');
}

// Password Reset Routes...
Route::get('password/reset', 'Auth\ForgotPasswordController@showLinkRequestForm')->name('password.request');
Route::post('password/email', 'Auth\ForgotPasswordController@sendResetLinkEmail')->name('password.email');
Route::get('password/reset/{token}', 'Auth\ResetPasswordController@showResetForm')->name('password.reset');
Route::post('password/reset', 'Auth\ResetPasswordController@reset');

This is a combination of some previous answers notably Rafal G. and Daniel Centore.

In routes.php, just add the following:

if (!env('ALLOW_REGISTRATION', false)) {
    Route::any('/register', function() {
        abort(403);
    });
}

Then you can selectively control whether registration is allowed or not in you .env file.

I had to use:

public function getRegister()
{
    return redirect('/');
}

Using Redirect::to() gave me an error:

Class 'App\Http\Controllers\Auth\Redirect' not found

In Laravel 5.4

You can find all routes which are registered through Auth::routes() in the class \Illuminate\Routing\Router in the method auth()

it looks like this:

/**
 * Register the typical authentication routes for an application.
 *
 * @return void
 */
public function auth()
{
    // Authentication Routes...
    $this->get('login', 'Auth\LoginController@showLoginForm')->name('login');
    $this->post('login', 'Auth\LoginController@login');
    $this->post('logout', 'Auth\LoginController@logout')->name('logout');

    // Registration Routes...
    $this->get('register', 'Auth\RegisterController@showRegistrationForm')->name('register');
    $this->post('register', 'Auth\RegisterController@register');

    // Password Reset Routes...
    $this->get('password/reset', 'Auth\ForgotPasswordController@showLinkRequestForm')->name('password.request');
    $this->post('password/email', 'Auth\ForgotPasswordController@sendResetLinkEmail')->name('password.email');
    $this->get('password/reset/{token}', 'Auth\ResetPasswordController@showResetForm')->name('password.reset');
    $this->post('password/reset', 'Auth\ResetPasswordController@reset');
}

Just copy the routes that you want/need and you are fine!

Heres my solution as of 5.4:

//Auth::routes();
// Authentication Routes...
Route::get('login', 'Auth\LoginController@showLoginForm')->name('login');
Route::post('login', 'Auth\LoginController@login');
Route::post('logout', 'Auth\LoginController@logout')->name('logout');

// Registration Routes...
//Route::get('register', 'Auth\RegisterController@showRegistrationForm')->name('register');
//Route::post('register', 'Auth\RegisterController@register');

// Password Reset Routes...
Route::get('password/reset', 'Auth\ForgotPasswordController@showLinkRequestForm')->name('password.request');
Route::post('password/email', 'Auth\ForgotPasswordController@sendResetLinkEmail')->name('password.email');
Route::get('password/reset/{token}', 'Auth\ResetPasswordController@showResetForm')->name('password.reset');
Route::post('password/reset', 'Auth\ResetPasswordController@reset');

Notice I've commented out Auth::routes() and the two registration routes.

Important: you must also make sure you remove all instances of route('register') in your app.blade layout, or Laravel will throw an error.

In order not too change the code as it is, just create a middleware to detect if the request url is url('register'), then redirect to 404 or do wherever.

In laravel 5.3, you should override the default showRegistrationForm() by including the code below into the RegisterController.php file in app\Http\Controllers\Auth

    /**
     * Show the application registration form.
     *
     * @return \Illuminate\Http\Response
     */
    public function showRegistrationForm()
    {
        //return view('auth.register');
         abort(404);  //this will throw a page not found exception
    }

since you don't want to allow registration, it's better to just throw 404 error so the intruder knows he is lost. And when you are ready for registraation in your app, uncomment //return view('auth.register'); then comment abort(404);

\\\\\\\\\\\\\\\\\\\\JUST AN FYI///////////////////////////////

If you need to use multiple authentication like create auth for users, members, students, admin, etc. then i advise you checkout this hesto/multi-auth its an awesome package for unlimited auths in L5 apps.

You can read more abouth the Auth methodology and its associated file in this writeup.