> For the complete documentation index, see [llms.txt](https://developers.weglot.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developers.weglot.com/wordpress/autoswitch-system-server-side-and-client-side-implementation.md).

# Autoswitch System: Server-Side and Client-Side implementation

By default, Weglot provides a **server-side auto-switch** that redirects visitors to the language version matching their browser settings. This works well in most cases, but caching systems or plugins that alter the request/response cycle can prevent the redirect from firing as expected.

To work around those limitations, Weglot can also run the auto-switch **client-side**, using its JavaScript library.

#### 1. Disable the server-side auto-switch

In your WordPress admin, go to **Weglot → Settings** and turn off the **Auto-switch** option.

#### 2. Enable the client-side auto-switch

Install and activate the [Code Snippets](https://wordpress.org/plugins/code-snippets/) plugin, then go to **Snippets → Add New**, give it a title (e.g. `Weglot - Autoswitch JS`), paste the code below, and save:

```php
function custom_weglot_empty_selectors( $selectors ) {
    return [];
}
add_filter( 'weglot_whitelist_selectors', 'custom_weglot_empty_selectors' );
add_filter( 'weglot_dynamics_selectors', 'custom_weglot_empty_selectors' );

add_filter( 'weglot_translate_dynamics', '__return_true' );
add_filter( 'weglot_allowed_urls', function () {
    return 'all';
} );
add_filter( 'weglot_autoredirect_js', '__return_true' );
```

What each filter does:

* **`weglot_translate_dynamics`** — loads Weglot's JavaScript library on the page (required for client-side switching).
* **`weglot_allowed_urls`** — returning `'all'` loads the script on every page; without it the script never loads.
* **`weglot_whitelist_selectors` / `weglot_dynamics_selectors`** — returning an empty array disables dynamic content translation, so the library only performs the auto-switch redirect and doesn't re-translate the page on the fly.
* **`weglot_autoredirect_js`** — the key filter: it turns the client-side auto-switch on.

You can add these filters through Code Snippets, an mu-plugin, or your theme's `functions.php`.

With this setup, Weglot performs the language auto-switch **client-side via JavaScript**, keeping it compatible with caching systems and other plugins that interfere with server-side redirects.