Verify server encoding capabilities
Before converting format configurations, verify your hosting server’s capabilities. PHP GD and Imagick libraries must compile support for WebP and AVIF formats natively. If a plugin attempts to output format options that the host server cannot compile, the generation will fail or return broken files.
Cyphex includes a dashboard checks panel that queries `gd_info()` and `Imagick::queryFormats()` to confirm format capabilities, disabling unsupported options automatically to prevent runtime failures.
Serve sibling formats via picture elements
Replacing original attachments destructively breaks external links and cached social media thumbnails. Sibling format delivery creates WebP/AVIF versions alongside the original image file under the same directory, keeping the original file as a fallback.
HTML5 `<picture>` tags allow the browser to parse source formats. Modern devices load the AVIF or WebP files, while older browsers load the fallback JPEG/PNG from the original URL, ensuring 100% compatibility.
Avoid conflicting rewriting systems
Running multiple image converter plugins concurrently leads to broken layouts and server errors. If your caching plugin, theme, or CDN is already rewriting image HTML to serve WebP, enabling another conversion layer can nesting picture elements incorrectly.
Choose one plugin to manage format sibling generation and markup delivery. Run a test build, examine the frontend source HTML, and verify that the LCP image resolves to WebP or AVIF.