Spinix Image Optimization

FAQ

What happens to my images if I remove the plugin?

Nothing. Your original images are never modified. Optimized copies live in the spinix-webp folder inside your uploads folder. When you delete the plugin, that folder and all plugin settings are removed (you can turn this off under Settings → When you uninstall).

My server says WebP is not supported

Ask your hosting company to enable WebP support in the GD or Imagick PHP extension. Most hosts can switch it on in a minute. The Tools tab shows exactly what is missing.

Does it work with caching plugins and CDNs?

Yes. The WebP markup is written into the page itself, so cached pages and CDNs serve it like any other HTML. Clear your page cache after the first bulk optimization.

Another plugin also lazy-loads images or prioritizes the hero image. Is that a problem?

No. Spinix Image Optimization detects WP Rocket, Elementor, Perfmatters, FlyingPress, Autoptimize, LiteSpeed Cache and other common plugins and lets you choose which plugin handles lazy loading and the hero image, so nothing is done twice.

Can I use it together with another image optimizer?

Two image optimizers on one site convert and rewrite the same images and break each other. Spinix Image Optimization therefore asks you to deactivate the other optimizer first, and pauses itself if one is activated later.

How does hero image priority work? Automatic or manual?

Automatic (the default, on every page): Spinix looks below your site header and takes the first large image or background image. A normal image gets fetchpriority="high" and is never lazy-loaded. A background image (Elementor, other page builders, inline styles) is preloaded in the page head with fetchpriority="high", with a separate image for phones and tablets if your design uses one. Only this image gets priority, so other images no longer compete with it.

Manual (optional, per page): if PageSpeed Insights shows another image as the “Largest Contentful Paint element”, open that page in the editor and use the Spinix hero image box in the sidebar. Choose the right image, or switch hero priority off for that page. Pages you do not change stay automatic.

You can see what Spinix chose at the end of the page source: <!-- ... hero image = ... -->.

How can I compare a page with and without optimization?

Add ?spinix_io=off to the end of any page address. That page is then shown without Spinix Image Optimization.

Why are some images not served as WebP?

Spinix serves a WebP version only when it is really smaller than the original. Most photos become 40-80% smaller, but a few images do not: very small icons, simple graphics with only a few colours, or JPEGs that were already compressed very hard. For these, the WebP would be the same size or even bigger, and simple graphics can lose sharpness. Spinix therefore keeps serving the original, which is already the smallest file, and shows “Already optimal · Original kept”.

This does not cost you anything in PageSpeed Insights. Google only flags an image (“Improve image delivery” / “Serve images in next-gen formats”) when converting it would save a meaningful number of bytes, so an image that WebP cannot make smaller is not flagged.

Which images are optimized?

JPEG, PNG and WebP images in the Media Library, including all sizes WordPress creates. GIF files are left as they are so animations are kept, and SVG files are left untouched.

Does Spinix Image Optimization send my data anywhere?

No. All images are optimized on your own server. The plugin does not contact any external service, does not track you and collects no data. The “Test on PageSpeed” button only opens Google PageSpeed Insights in a new browser tab with your home page address when you click it.

Are there hooks for developers?

• spinix_io_webp_quality (int 1-100) – WebP quality.
• spinix_io_target_bytes_per_pixel (float, default 0.085) – target for PageSpeed-safe compression.
• spinix_io_mime_types (array) – image types to optimize.
• spinix_io_exclude_image (bool, string $tag) – leave an image untouched.
• spinix_io_process_page (bool) – skip optimization on a page.
• spinix_io_optimize_inline (bool) – return false to optimize uploads in the background instead of during the upload.
• spinix_io_fast_encoder (bool) – return false to always use the WordPress image editor.
• spinix_io_cron_time_budget (int seconds) – work per background run.
• spinix_io_write_htaccess (bool) – return false to skip the .htaccess file with cache headers in the spinix-webp folder.
• spinix_io_lookup_unknown_images (bool) – find images without a wp-image-ID class by their file name.
• spinix_io_hero (array $choice, int $post_id) – change the hero choice of a page: array( 'mode' => 'auto'|'image'|'off', 'id' => attachment ID ).
• spinix_io_optimized (action, int $id, array $data) – after an image was optimized.
• spinix_io_before_optimize (action, int $id) – before an image is optimized.
• spinix_io_image_row (array $row, int $id), spinix_io_media_status_html (string $html, int $id) – extend the Images list and the Media Library column.
• spinix_io_admin_settings (array), spinix_io_settings_saved (action, array $input) – add settings to the Settings tab (saved with the same Save button).
• spinix_io_admin_tabs, spinix_io_admin_panels, spinix_io_admin_dashboard, spinix_io_admin_settings_sections, spinix_io_admin_tools, spinix_io_admin_checklist (actions) – add parts to the screen. In JavaScript, window.spinixIo offers addFilter( 'hero' | 'rowFormats' | 'rowActions', fn ) and on( 'render' | 'rows' | 'row' | 'saved' | 'response', fn ).