ShortPixel Image Optimizer (SPIO) is designed to use minimal resources and only run when users with certain roles are logged in. This means that your website’s load speed should remain virtually unchanged for visitors, regardless of whether SPIO is optimizing images at that moment. However, some sites may experience different types of performance issues.
Important notes:
- The number 1 reason of speed issues on your website is your hosting provider. It is very common to experience slowness on low-cost shared hosting providers. Consider migrating to a better-performing server.
- If SPIO is used alone, it has practically no effect on the loading speed of websites. PluginTests has checked and confirmed this here. PluginTests is an independent testing platform for plugins that evaluates both memory consumption and possible effects on page speed metrics.
- Dashboard slower than usual: If you notice that your WordPress dashboard is slower while logged in as an admin, ShortPixel might be running in the background. To check if SPIO is the cause, stop the optimization process in Media Library > Bulk ShortPixel and see if performance improves.
- High CPU, disk, or RAM usage: Over the years, we’ve learned that resource usage varies depending on factors such as traffic, installed plugins, and available server resources. Below are some common causes and solutions:
- The “Optimize Retina images” option is active – This increases disk usage during image processing. You can find this option in the Image Optimization section of the ShortPixel settings. If it’s not needed, we recommend turning it off.
- The “Optimize unlisted thumbnails” option is active – Like the Retina option, this increases disk usage during optimization. If it’s unnecessary, disable it in the Image Optimization section.
- Too many thumbnails per image – WordPress generates 5 to 10 thumbnails by default, but if you have more than 10, consider excluding some of them from optimization. Each thumbnail requires processing, backup creation, and replacement, increasing server load.
- The “Convert PNG images to JPEG” option is active – This can significantly increase RAM usage. Large PNG files can consume over 100MB per process, and if multiple large PNGs are being optimized simultaneously, the server may become overloaded.
- Too many MySQL queries: Please read this article for more information.