colinleroy

This plugin has no setting or UI. It just does one thing : use the php-gettext library to handle translations. This results in much faster translation than using the default PHP gettext implementation of WordPress.
If the extension is not available, the plugin will simply do nothing.
You can verify that the plugin is working by looking for an HTTP header: X-Native-Gettext: 1, that will be sent as soon as a string will be translated by the native library.
If your WordPress install is in English, this plugin has no purpose. Otherwise, it can help speed up your install quite a lot.
Requirements: 
– php-gettext 
– OS-level support for the locale(s) you want to translate to.

Native Gettext for WordPress

Great Plugin.

It does one job and it does very good!

With the help of the Query Monitor Plugin, I was able to measure a drop of almost 45% of PHP memory usage using "Native Gettext for WordPress" for a simple Dashboard-request.
Really cool.

The plugin author is answering friendly and helpful to support requests.

Fast & Friendly

No problems found, after testing on several sites. My sites are all heavily dependent on fast loading of text domains, and all have the PHP gettext extension. PHP 8.0 and 8.1.

However, may not work in combination with other WordPress plugins overriding load_textdomain.


Works as it says, fast

A very light wrapper plugin that uses the native gettext library for faster localization.

nigro.simone

The translations reduces speed of WordPress.
For localized WordPress the loading time of translation files accounts for 30% of the entire processing time (less or more 40 milliseconds per page).
For each translation file, WordPress unpacks it and then everyone will be converted in an “Translation_Entry” object. This process, repeated at each page view, is a waste time and resource.
You can make this process 3 times faster by just installing this plugin. This plugin offers a caching solution using the WordPress standard cache mechanism that reduces this effects on performance.
Configurations are not required! You just have to install it and after the plugin does it all, none further action it’s required.
This plugin is very light: only 5 kB.
<h3>Features</h3>
<ul>
<li>No configuration</li>
<li>Supports multiple languages</li>
<li>Supports plugin’s translation files caching</li>
<li>Supports WordPress Network/Multisite installation</li>
<li>Cache automatically expire when translation file is updated</li>
</ul>
<h3>Recommended Installation</h3>
For better performance, verify that <code>/wp-content/object-cache.php</code> is installed (see https://codex.wordpress.org/Class_Reference/WP_Object_Cache#Persistent_Cache_Plugins).

Speed Up – Translation Cache

The translations reduces speed of Wordpress. This plugin offers a caching solution that reduces this effects on performance.

Native Gettext for WordPress vs Speed Up – Translation Cache