About this plugin
couic is a WordPress image optimizer for image compression, WebP and AVIF conversion, and responsive image delivery. Compress JPEG, PNG, WebP and AVIF files in your media library, optimize new uploads automatically, or process existing images in bulk.
Large image uploads can also be resized locally before WordPress creates thumbnails. The browser diagnostic helps administrators check which image actually loaded, its file size and whether its dimensions suit the page layout and screen density.
Remote compression works on shared hosting without exec(). Connect a couic account or configure your own trusted couic endpoint. The plugin sends images to that service, validates the results and saves smaller variants alongside the source.
The connected service may require a paid subscription. Local upload resizing and browser diagnostics do not require remote optimization.
Image compression and WebP/AVIF conversion
Choose normal, aggressive or ultra compression. Generate WebP and AVIF variants and deliver responsive images while preserving the existing sizes attribute. A returned image is saved only when it has a valid format, matching dimensions and a smaller file size.
Existing picture elements are preserved, and incomplete converted thumbnail sets keep the original image choices.
Resize large uploads and keep control of originals
The default maximum upload width is 2560 pixels. Set it to zero to disable local resizing. Original preservation, backups and remote optimization are separate settings.
You can retry failed images, exclude individual images or thumbnail sizes, and restore saved originals.
Check the images visitors actually load
The administrator-only diagnostic reports the selected image source, file dimensions, file size, rendered dimensions and screen density. Export the results as JSON to review oversized or undersized images and choose files that fit the displayed size.
For logos, theme images and CSS backgrounds outside the media library, generate responsive copies from selected directories inside wp-content. Copy the HTML with sizes and alternative text, or select an explicit width for your CSS background. Source files remain intact.
Features:
* Automatic background optimization of uploads using Action Scheduler when available, otherwise WordPress Cron.
* Bulk optimization with progress, pause and resume, including pending images, the entire library or failed images.
* Normal, aggressive and ultra compression levels.
* JPEG, PNG, WebP and AVIF inputs; WebP and AVIF output variants.
* Local upload resizing before thumbnail generation, with a default maximum width of 2560 pixels. Set zero to disable resizing.
* Optional original replacement with backups, or preserve originals.
* Responsive picture delivery that preserves sizes and skips incomplete converted thumbnail sets; optional Apache rewrite delivery.
* Detection of new or modified thumbnails without sending unchanged files again.
* Media library status filters, retry, restore and per-image or per-size exclusions.
* Available-variant savings estimates and a local monthly usage indicator.
* Optimization of selected directories inside wp-content.
* Responsive copies for selected images outside the media library, with configurable widths, sizes, alternative text and explicit CSS background width choices.
* Administrator-only browser diagnostics for loaded image dimensions, bytes, rendered size, screen density and JSON export.
External services
app. app in your browser and exchanges a short-lived authorization code for a site-specific API token. app/api/optimize.
For each requested optimization, the plugin sends the image file, site token (Bearer authentication), compression level, requested output formats, maximum dimensions and metadata preference. Requests happen after uploads, when changed thumbnails are detected with automatic optimization enabled, during bulk or directory optimization, and when you manually generate responsive copies. The service processes images without storing them.
No WordPress user accounts or page content are sent. The connected service meters usage against your couic account; a paid subscription may be required according to the applicable couic offer.
app/cgv
app/confidentialite
You may instead configure your own trusted couic endpoint. Its operator determines its terms and privacy policy. No images are sent before a service URL and token are configured.
Local upload resizing and the browser diagnostic do not require the remote API. The diagnostic runs in the administrator’s browser; its JSON export is saved locally and not sent to couic.
Known limitations
- GIF and SVG inputs are passed through without optimization.
- Existing picture elements are preserved.
- The local monthly usage indicator does not impose a quota.
- CSS background copies require an explicit width selection; the plugin does not rewrite your stylesheets.
- Diagnostic measurements may be unavailable for external, embedded or unloaded images. Network transfer bytes and decoded file bytes are distinct measurements.