Quite Nice Stuff

Iris Translate provides flexible website translation with two distinct methods to suit your needs:
Automatic Mode (Free) – Uses Google Translate’s client-side widget for instant translation with no setup required.
Google Cloud API Mode – Server-side translation with SEO-friendly translated URLs, hreflang tags, and full search engine indexability. Free for most websites (see below).
<h4>Key Features</h4>
Translation Methods
<ul>
<li>Automatic Translation – Free client-side translation using Google Translate widget, no API key needed</li>
<li>Google Cloud API Translation – Server-side translation for SEO-friendly, indexable translated content</li>
<li>Configurable fade-in delay to hide flash of untranslated content (Automatic mode)</li>
</ul>
SEO & URL Translation
<ul>
<li>SEO-friendly translated URLs (e.g., <code>/fr/a-propos/</code> instead of <code>/about/</code>)</li>
<li>Automatic hreflang tag generation for proper search engine indexing</li>
<li>Translated URL management interface with bulk translation tools</li>
<li>Individual URL path customization per language</li>
</ul>
Custom Translation Overrides
<ul>
<li>Override any automatic translation with your own custom text</li>
<li>Frontend translation editor for logged-in administrators</li>
<li>Edit translations directly on the page while browsing your translated site</li>
<li>Manage all custom translations from the admin dashboard</li>
</ul>
Language Selector Widgets
<ul>
<li>Multiple widget styles: Dropdown, Dropdown with flags, List, List with flags</li>
<li>Floating language selector with configurable position (corners of the screen)</li>
<li>Widget support for sidebars</li>
<li>Shortcode support: <code>[iris_translate]</code></li>
<li>PHP function support for theme integration</li>
<li>Display language names in their native script (e.g., “日本語” instead of “Japanese”)</li>
</ul>
Supported Languages
Over 25 languages supported including: English, Spanish, French, German, Italian, Portuguese, Dutch, Russian, Japanese, Korean, Chinese (Simplified & Traditional), Arabic, Hindi, Turkish, Polish, Swedish, Norwegian, Danish, Finnish, Greek, Czech, Romanian, Hungarian, Thai, Vietnamese, and Indonesian.
<h3>External Services</h3>
This plugin connects to Google services to provide translation functionality. By using this plugin, you agree to Google’s terms of service.
<h4>Automatic Translation Mode</h4>
When using Automatic Translation mode, this plugin loads the Google Translate Widget from Google’s servers.
What this service does: Provides client-side (in-browser) translation of your website content.
When data is sent: When a visitor selects a language to translate to, their browser communicates directly with Google Translate servers to fetch translations.
What data is sent: 
* The text content of the webpage being translated 
* The visitor’s IP address (sent by their browser to Google) 
* Browser cookies set by Google (including the <code>googtrans</code> cookie to remember language preference)
Service provider: Google LLC
Links: 
* <a href="https://translate.google.com/" rel="nofollow ugc">Google Translate</a> 
* <a href="https://policies.google.com/privacy" rel="nofollow ugc">Google Privacy Policy</a> 
* <a href="https://policies.google.com/terms" rel="nofollow ugc">Google Terms of Service</a>
<h4>Google Cloud API Translation Mode</h4>
When using Google Cloud API mode, this plugin sends content to the Google Cloud Translation API for server-side translation.
What this service does: Provides server-side translation of your website content, enabling SEO-friendly translated URLs.
When data is sent: 
* When a visitor accesses a translated URL (e.g., <code>/fr/your-page/</code>), the page content is sent to Google for translation 
* When an administrator uses the “Translate All URLs” feature to bulk-translate URL slugs 
* Translations are cached locally to minimize API calls
What data is sent: 
* The text content of pages and posts being translated 
* URL slugs when using the URL translation feature 
* Your Google Cloud API key (for authentication)
What data is NOT sent: 
* Visitor IP addresses (translation happens on your server, not in the visitor’s browser) 
* Personal visitor information 
* User account data
Service provider: Google Cloud (Google LLC)
Links: 
* <a href="https://cloud.google.com/translate" rel="nofollow ugc">Google Cloud Translation API</a> 
* <a href="https://cloud.google.com/terms/cloud-privacy-notice" rel="nofollow ugc">Google Cloud Privacy Policy</a> 
* <a href="https://cloud.google.com/terms" rel="nofollow ugc">Google Cloud Terms of Service</a> 
* <a href="https://cloud.google.com/translate/pricing" rel="nofollow ugc">Google Cloud Translation API Pricing</a> (includes free tier)
<h4>Cookies</h4>
This plugin sets the following cookie:
<ul>
<li>googtrans – Stores the visitor’s selected language preference. This is a session cookie used by Google Translate to remember which language the visitor chose. No personal data is stored in this cookie.</li>
</ul>
<h4>Data Privacy</h4>
<ul>
<li>In Automatic mode, translation processing occurs on Google’s servers via the visitor’s browser</li>
<li>In Google Cloud API mode, translation processing occurs on Google’s servers but is initiated by your WordPress server, not the visitor’s browser</li>
<li>Translated content is cached in your WordPress database to improve performance and reduce external API calls</li>
<li>No visitor personal data is collected or stored by this plugin</li>
<li>No visitor tracking is performed by this plugin beyond the language preference cookie</li>
</ul>

Iris Translate

Translate your WordPress site with free automatic translation or SEO-friendly Google Cloud API translation.

jenz

The SDAC Translate plugin uses Google Translate to translate your site’s content in multiple languages using a simple sidebar widget that is fully customizable.
<h3>Notes</h3>
<ol>
<li>I wanted to keep this plugin as lightweight as possible so the widget output is cached and the images are all in one image.</li>
<li>If you have non-standard plugin directory – see line 24 on how to add that into the plugin to make the images appear correctly.</li>
</ol>

SDAC Translate

Simple lightweight translation sidebar widget that uses Google Translation.

Iris Translate vs SDAC Translate