# Use custom language code (URL, lang and hreflang attribute)
Here, we explain how to change the default language code. This is useful if you don't like the default 2 letters code of Weglot in the URL and want to change it into another language code.
### Example: Changing "tw" to "zh-HK"
In this post, we show for example how to change language code tw (Traditional Chinese) to zh-HK (Hong Kong Chinese).
```markup
```
### Hook for customize language code
This hook must be load before your theme. This is why you can not use it in your `functions.php`. To use it, you can follow one of the 2 method below.
```php
// Use zh-HK (Hong Kong Chinese) instead tw (Traditional Chinese)
add_filter( 'weglot_language_code_replace', 'custom_weglot_language_code_replace' );
function custom_weglot_language_code_replace( $replacements ) {
$replacements['tw'] = 'zh-HK';
return $replacements;
}
// Use tw instead of zh-HK on hreflangs (optional)
add_filter( 'weglot_href_lang', 'custom_weglot_href_lang' );
function custom_weglot_href_lang( $render ) {
$render = str_replace("hreflang=\"zh-HK\"", "hreflang=\"tw\"", $render);
return $render;
}
```
### Update for autoredirection option
If you've activate the autoredirection option, you should be use this other filter to add your custom code into the navigator language list
```
add_filter( 'weglot_navigator_language', 'custom_weglot_navigator_language' );
function custom_weglot_navigator_language( $navigator_languages ) {
$navigator_languages = array();
if ( isset( $_SERVER['HTTP_ACCEPT_LANGUAGE'] ) ) { //phpcs:ignore
$navigator_languages = explode( ',', trim( sanitize_text_field( $_SERVER['HTTP_ACCEPT_LANGUAGE'] ) ) );
foreach ( $navigator_languages as &$navigator_language ) {
if ( strpos( $navigator_language, ';' ) !== false ) {
$navigator_language = substr( $navigator_language, 0, strpos( $navigator_language, ';' ) );
}
$navigator_language = strtolower( $navigator_language );
$navigator_language = str_replace('tw', 'zh-HK', $navigator_language);
}
}
return $navigator_languages;
}
```
### Method 1: Use plugin Code Snippets
1. Add and activate Code Snippets plugin on your WordPress:
2. In your WordPress back office, go to Snippets -> Add new
3. Add a title (example: `Weglot - Custom language code`)
4. Add the following code into the code input. Don't copy `