PHP code snippets and embeds

WordPress Playground ships two ready-made ways to put runnable PHP — and the full WordPress runtime — directly into a web page or a shareable URL. No PHP server, no setup, just a browser.

<php-snippet> web component — drop one <script> tag into your blog post, docs site, or readme to embed multiple runnable PHP snippets that share a single Playground runtime.
Standalone PHP Playground — a full-page PHP editor at playground.wordpress.net/php-playground.html with a shareable URL.

Embedding with `<php-snippet>`

The <php-snippet> custom element renders a syntax-highlighted code block with a Run button. Multiple snippets on the same page share a single hidden Playground runtime that is downloaded only when the visitor clicks Run for the first time.

Quick start

<script
	type="module"
	src="https://playground.wordpress.net/php-code-snippet.js"
></script>

<php-snippet name="hello.php">
	<script type="application/x-php">
<?php
echo "Hello from PHP " . phpversion();
	</script>
</php-snippet>

That's the whole integration. The script is around 5 KB gzipped and contains no PHP or WordPress — those are fetched lazily on the first Run click.

Why a `<script type="application/x-php">` wrapper?

Browsers ignore the contents of script tags whose type they don't understand. That means you can put PHP code that contains literal < characters (HTML strings, generics, comparisons) inside the wrapper without escaping anything.

If your snippet has no characters that need escaping, you can put the code directly inside <php-snippet>:

<php-snippet name="add.php">
	&lt;?php echo 1 + 2;
</php-snippet>

You can also load the code from a separate file:

<php-snippet name="lazy-load.php" src="./snippets/lazy-load.php"></php-snippet>

WordPress is available

Each snippet runs inside a real WordPress installation. require '/wordpress/wp-load.php' brings in the core APIs:

<php-snippet name="lazy-load-images.php">
	<script type="application/x-php">
<?php
require '/wordpress/wp-load.php';

$html = '<article>
    <img src="hero.jpg" alt="Hero">
    <img src="inline.jpg" alt="Inline">
</article>';

$tags = new WP_HTML_Tag_Processor( $html );
while ( $tags->next_tag( 'img' ) ) {
    $tags->set_attribute( 'loading', 'lazy' );
    $tags->add_class( 'responsive' );
}

echo $tags->get_updated_html();
	</script>
</php-snippet>

The first time a visitor clicks Run on any snippet on the page, the component:

Lazy-loads the Playground client (https://playground.wordpress.net/client/index.js),
Creates one hidden iframe pointing at https://playground.wordpress.net/remote.html,
Boots PHP and WordPress inside it.

Every later Run — on the same snippet or any other — calls client.run({ code }) against that same runtime. No additional downloads, no extra processes. A page with five snippets pays the runtime cost once.

While the boot is in progress, every snippet that has its Run clicked shows the same staged progress bar (download → install → ready) drawn from the live progress events Playground emits internally.

Editable snippets

Add the editable attribute and visitors can tweak the code before clicking Run. The keystrokes go into a transparent textarea overlaid on the highlighted code, so the syntax colors update as they type.

<php-snippet name="scratch.php" editable>
	<script type="application/x-php">
<?php
$nums = range(1, 10);
echo "Sum: " . array_sum($nums);
	</script>
</php-snippet>

Useful for "now you try" sections in tutorials, or for letting readers experiment with their own values. Edits live only in the page — there's no persistence — so a refresh resets the snippet to its initial code.

Attributes

Attribute	Default	Purpose
`name`	`snippet.php`	Filename label shown in the snippet header
`php`	`8.4`	PHP version (see supported versions)
`wp`	`latest`	WordPress version
`src`	—	Load PHP from a URL instead of inline
`editable`	(off)	Let visitors edit the code before running
`playground-origin`	`https://playground.wordpress.net`	Override the runtime origin (local dev, etc.)

Snippets that share the same php, wp, and playground-origin values share one runtime; mixing different versions on the same page boots a separate runtime per combination.

Standalone PHP Playground

For full-page editing or sharing a one-off snippet via URL, use the standalone PHP Playground at:

playground.wordpress.net/php-playground.html

It's a side-by-side editor and preview with PHP and WordPress version selectors. The current code, PHP version, and WordPress version are encoded into the URL fragment, so you can share a working example by copying the URL.

You can embed it in any page with an iframe:

<iframe
	src="https://playground.wordpress.net/php-playground.html#eyJjb2RlIjoiPD9waHBcblxuZWNobyBcIkkgYW0gYSBjb2RlIHNuaXBwZXQhXCI7XG4iLCJwaHAiOiI4LjQifQ=="
	width="100%"
	height="600"
></iframe>

The fragment is a base64-encoded JSON payload of { code, php, wp }.

Standalone PHP Playground `<iframe>` vs. `<php-snippet>` — which should I use?

Use case	Pick
Multiple read-only runnable examples in a docs page or blog post	`<php-snippet>`
Customizations, e.g. read-only code vs editable code	`<php-snippet>`
A single code example you don't want to load foreign scripts on your site	Standalone PHP Playground

Embedding with <php-snippet>​

Quick start​

Why a <script type="application/x-php"> wrapper?​

WordPress is available​

How runtime sharing works​

Editable snippets​

Attributes​

Standalone PHP Playground​

Standalone PHP Playground <iframe> vs. <php-snippet> — which should I use?​