What this problem is
Images look blurry or are displayed at the wrong size after a theme change or resizing settings.
Why it happens
- Thumbnail sizes changed but old thumbnails remain
- Theme uses different image sizes
- Retina/hiDPI handling misconfigured
Prerequisites
- Admin access and a thumbnail regeneration tool
Diagnosis
Inspect the image URL to see which size is being used (thumbnail/medium/large). Compare to desired dimensions.
Detailed steps
Step 1) Confirm image size settings
Settings > Media: verify thumbnail/medium/large sizes; also check theme settings.
Step 2) Regenerate thumbnails
Use a trusted plugin to regenerate thumbnails for the media library.
Step 3) Clear caches
Purge cache and CDN to ensure new thumbnails are served.
Expected results
- Images display crisp at the correct size
What to do if it fails
- Check if the theme or builder forces a specific size or uses background images that are not regenerated
Best practices
- Define standard image sizes and avoid changing them frequently on production