Why WebP helps a WordPress site
A WebP image is typically 25 to 35 percent smaller than the same JPG or PNG at similar quality. Smaller images mean faster page loads, a better experience on mobile data and better page experience scores, which search engines take into account. WebP also supports transparency, so it can replace PNG for logos.
Step 1: Convert your images
- Photos: use JPG to WebP.
- Logos, screenshots and graphics: use PNG to WebP.
- iPhone photos: use HEIC to WebP to skip the JPG step.
You can drop dozens of files at once and download them all as a ZIP.
Step 2: Pick the right size
Upload images at the size your theme actually shows, not straight from the camera. Under Options, choose Resize:
- Max 1920px for full-width headers and hero images.
- Max 1280px for featured images and images inside posts on most themes.
- Max 800px for thumbnails and images in narrow columns.
WordPress still creates its own smaller copies (thumbnail, medium, large) from what you upload, so starting with a sensible size keeps every copy small.
Step 3: Pick the right quality
Quality 75 is a good default for photos. Use 85 or more for images with text, such as screenshots and infographics. Check one image at full size before converting a whole batch.
Step 4: Upload to the Media Library
Upload the WebP files in Media, Add New, exactly like JPG or PNG. Fill in the Alt Text field with a short description of each image: it helps visitors using screen readers and helps search engines understand the picture. A descriptive file name, such as blue-running-shoes.webp, helps too.
Common problems
- "Sorry, you are not allowed to upload this file type." Your WordPress is older than 5.8, or your host blocks WebP. Update WordPress, or ask your host.
- Thumbnails are missing. The server's image library cannot process WebP. Most hosts support it; ask yours to enable WebP support in GD or Imagick.
- The WebP is bigger than the JPG. The JPG was already compressed very hard. Lower Quality to 65, or keep the JPG.