How to read URL parameters in laravel
Stefan Bogdanescu
Founder & Senior Architect · 2026-06-29
# Mastering URL Parameters in Laravel: Building Referral Systems from Scratch
As a senior developer, I often see beginners encounter hurdles when trying to extract dynamic data embedded within URLs. For building features like referral systems, understanding how Laravel handles incoming request data is fundamental. When you are starting with something as powerful as the Laravel framework, mastering the Request object is your key to unlocking dynamic application behavior.
This post will walk you through exactly how to read URL parameters in Laravel, specifically focusing on your referral system example, and clarify the role of middleware versus query strings.
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## Understanding URL Parameters: Query Strings Explained
When a user navigates to a URL like `http://dev.lea.com/register?ref=mh2HPLpVSn`, the part after the question mark (`?`) and the subsequent key-value pairs (`ref=mh2HPLpVSn`) are known as **Query Parameters**. These parameters are used to pass data from the client (the browser) to the server when making a request.
In Laravel, all incoming request data—whether it's form submissions, URL parameters, or cookie data—is accessed through the `Illuminate\Http\Request` object. This object provides powerful methods for safely retrieving this information.
## How to Extract Referral Data in Your Controller
To retrieve the `ref` parameter from your sample URL within your `RegisterController`, you use the `input()` method or the `query()` method on the request object. Using these methods is far superior to manually parsing the raw URL string.
Here is how you would modify your controller method to correctly access the referral link:
```php
input('ref');
// You can now use this code for tracking or assigning an affiliate ID
echo "Referral Code Received: " . $referral_code;
// Example: Store the referral code in the database if needed
// $user = User::create([
// // ... other fields
// 'referred_by' => $referral_code,
// ]);
return User::create([
'fname' => $data['fname'],
'lname' => $data['lname'],
'username' => $data['username'],
'email' => $data['email'],
'password' => bcrypt($data['password']),
'affiliate_id' => str_random(10),
// 'referred_by' => $referral_code, // Store it here!
'identity' => $data['identity'],
'dob' => $data['dob'],
// ... rest of the data
]);
}
}
```
Notice how clean this is. Instead of relying on raw string manipulation or complex middleware for simple parameter passing, Laravel handles all the heavy lifting through the `$request` object. This approach aligns perfectly with the MVC principles taught by organizations like [Laravel Company](https://laravelcompany.com).
## Middleware vs. Query Parameters: When to Use What?
You asked about using middleware for cookies versus reading URL parameters. This is a critical distinction:
1. **URL Parameters (Query Strings):** These are best for passing transient, context-specific data *for that specific request*. Since the referral link is tied directly to the registration action, reading it from the query string (`?ref=...`) and using it immediately in the controller is the most straightforward method.
2. **Cookies:** Cookies are designed for maintaining **state** across multiple requests (e.g., keeping a user logged in, remembering user preferences). If you needed to store the referral ID persistently so that subsequent actions reference it, then storing it in the database associated with the user, or using session data managed by Laravel, would be the better long-term solution than relying solely on cookies for this specific task.
For your immediate goal of capturing the referral link upon registration, reading the parameter directly from `$request->input('ref')` is the most efficient and appropriate technique.
## Conclusion
By leveraging the `Request` object in Laravel, you transform complex data retrieval into simple, readable code. For your referral system, extracting the `ref` parameter from the URL query string is the correct approach. Remember that for state management (like user sessions or persistent tracking), use the proper tools—database models and session/cookie management—while using URL parameters for immediate request context. Keep experimenting with Laravel's powerful features; they make complex applications manageable!