# How to use forms in PHP

> Learn how to handle forms in PHP, reading submitted data from the $_GET and $_POST superglobals and moving the form handler into a separate post.php file.

Author: [Flavio Copes](https://flaviocopes.com/about/) | Published: 2022-08-29 | Topics: [PHP](https://flaviocopes.com/tags/php/) | Canonical: https://flaviocopes.com/php-forms/

Forms are the way the Web platform allows users to interact with a page and send data to the server.

Here is a simple form in HTML:

```php
<form>
  <input type="text" name="name" />
  <input type="submit" />
</form>
```

You can put this in your `index.php` file like it was called `index.html`.

A PHP file assumes you write HTML in it with some “PHP sprinkles” using `<?php ?>`, so the Web Server can post that to the client. Sometimes the PHP part takes all of the page, and that’s when you generate all the HTML via PHP - it’s kind of the opposite of the approach we do here now.

So we have this `index.php` file that generates this form using plain HTML:

![A simple HTML form with a text input field and Submit button displayed in a web browser](https://flaviocopes.com/images/php-forms/Screen_Shot_2022-06-27_at_13.53.47.jpg)

Pressing the Submit button will make a GET request to the same URL sending the data via query string, notice the URL changed to [localhost:8888/?name=test](http://localhost:8888/?name=test)

![Browser showing form after GET submission with name=test parameter visible in the URL](https://flaviocopes.com/images/php-forms/Screen_Shot_2022-06-27_at_13.56.46.jpg)

We can add some code to check if that parameter is set using the [`isset()`](https://www.php.net/manual/en/function.isset.php) function

```php
<form>
  <input type="text" name="name" />
  <input type="submit" />
</form>

<?php
if (isset($_GET['name'])) {
  echo '<p>The name is ' . $_GET['name'];
}
?>
```

![Form displaying The name is test message below the Submit button after processing the GET request](https://flaviocopes.com/images/php-forms/Screen_Shot_2022-06-27_at_13.56.35.jpg)

See? We can get the information from the [GET request](https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/GET) query string through `$_GET`.

What you usually do with forms however is, you perform a POST request:

```php
<form **method="POST"**>
  <input type="text" name="name" />
  <input type="submit" />
</form>

<?php
if (isset($_POST['name'])) {
  echo '<p>The name is ' . $_POST['name'];
}
?>
```

See, now we got the same information but the URL didn’t change, the form information was not appended to the URL.

![Form displaying The name is test message after POST submission without query string in the URL](https://flaviocopes.com/images/php-forms/Screen_Shot_2022-06-27_at_13.59.54.jpg)

This is because we’re using a [POST request](https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/POST), which sends the data to the server in a different way, through urlencoded data.

As mentioned, PHP will still serve the `index.php` file as we’re still sending data to the same URL the form is on.

We’re mixing a bunch of code and we could separate the form request handler from the code that generates the form.

So we can have in `index.php` this:

```php
<form **method="POST" action="/post.php"**>
  <input type="text" name="name" />
  <input type="submit" />
</form>
```

and we can create a new `post.php` file with:

```php
<?php
if (isset($_POST['name'])) {
  echo '<p>The name is ' . $_POST['name'];
}
?>
```

PHP will display this content now after we submit the form, because we set the `action` HTML attribute on the form.

This example is very simple, but the `post.php` file is where we could for example save the data to the database, or to a file.