Route Fallback: If No Other Route is Matched

Laravel 5.5.5 introduced a new feature in routing, called Route::fallback(). Basically, if no route is matched, then fallback function is a way to override default 404 page and introduce additional logic. Here's how it works.

In your routes/web.php file, at the very end, after all the routes, you can specify something like this:

Route::group(['middleware' => ['auth'], 'prefix' => 'admin', 'as' => 'admin.'], function () {
    Route::get('/home', 'HomeController@index');
    Route::resource('tasks', 'Admin\TasksController');
});

// Some more routes....

Route::fallback(function() {
    return 'Hm, why did you land here somehow?';
});

And if someone enters random URL like yourdomain.com/abcde12345, here's what will show up:

Note, that this Route::fallback() method should go at the very end of routes file, after everything.

Another side effect of this: instead of just default 404 page, this Route::fallback() will follow all the Middlewares in 'web' group, from app/Http/Kernel.php:

protected $middlewareGroups = [
    'web' => [
        \App\Http\Middleware\EncryptCookies::class,
 \Illuminate\Cookie\Middleware\AddQueuedCookiesToResponse::class,
        \Illuminate\Session\Middleware\StartSession::class,
        // \Illuminate\Session\Middleware\AuthenticateSession::class,        \Illuminate\View\Middleware\ShareErrorsFromSession::class,
        \App\Http\Middleware\VerifyCsrfToken::class,
        \Illuminate\Routing\Middleware\SubstituteBindings::class,
    ],