How to Redirect Uppercase URLs to Lowercase with Laravel Middleware

Last week, I needed to redirect all requests that contained uppercase letters to their lowercase equivalents for SEO optimization.

For example:

At the same time, the solution shouldn't change any query parameters:

It turns out we can do this with just a few lines of code in a Laravel middleware! First, we grab the path from the request and check if the it is the same lowercased. If not, we can use the url()->query() method to append the query string back onto the lowercase version of the path and permanently redirect to the lowercased path.

<?php
 
namespace App\Http\Middleware;
 
use Closure;
use Illuminate\Http\Request;
use Symfony\Component\HttpFoundation\Response;
 
class RedirectUppercase
{
    /**
     * Handle an incoming request.
     *
     * @param  \Closure(\Illuminate\Http\Request): (\Symfony\Component\HttpFoundation\Response)  $next
     */
    public function handle(Request $request, Closure $next): Response
    {
        $path = $request->path();
 
        if (($lower = strtolower($path)) !== $path) {
            $url = url()->query($lower, $request->query());
 
            return redirect($url, 301);
        }
 
        return $next($request);
    }
}

To register the middleware in a Laravel 11 app, I appended it to the web middleware group in the bootstrap/app.php file.

<?php
 
return Application::configure(basePath: dirname(__DIR__))
    ->withRouting(
        // ...
    )
    ->withMiddleware(function (Middleware $middleware) {
        $middleware->appendToGroup('web', \App\Http\Middleware\RedirectUppercase::class);
    });

Note: you may want to exclude this middleware from routes that use signed URLs or other case sensitive use-cases.

I'm sure there are possible solutions with Nginx or Apache, but this was by far the simplest solution for me and it works across all environments of the app. I don't have to remember to make any changes on new servers.