WebP is a modern image format developed by Google that provides superior compression compared to traditional formats like JPEG and PNG. It supports both lossy and lossless compression, transparency (alpha channel), and even animation — all in a single format with significantly smaller file sizes.
WebP vs. Traditional Formats
Here's how WebP compares to the formats it aims to replace:
- vs. JPEG — WebP lossy images are typically 25-34% smaller than JPEG at equivalent visual quality. For photos and complex images, this translates to faster load times without visible quality loss.
- vs. PNG — WebP lossless images are about 26% smaller than PNG. WebP also supports transparency, making it a direct replacement for PNG in most cases.
- vs. GIF — WebP supports animation with much better compression than GIF, producing files that are significantly smaller.
Browser Support
WebP is supported by all modern browsers:
- Chrome (since 2014)
- Firefox (since 2019)
- Edge (since 2018)
- Safari (since 2020, macOS Big Sur / iOS 14)
- Opera (since 2014)
As of 2025, WebP is supported by over 97% of browsers worldwide, making it safe to use as the primary image format.
Why WebP Matters for WordPress
- Faster page loads — Smaller images mean less data to transfer, directly improving page speed.
- Better Core Web Vitals — Smaller images improve Largest Contentful Paint (LCP), a key Google ranking factor.
- Lower hosting costs — Less bandwidth consumption and storage usage.
- SEO benefit — Google recommends serving images in next-gen formats like WebP.
WebP in WordPress
WordPress has supported WebP uploads natively since version 5.8 (2021). When you upload a WebP image to the Media Library, WordPress generates all the standard image sizes (thumbnail, medium, large) in WebP format.
AVIF: The Next Generation
AVIF is an even newer image format that offers better compression than WebP (typically 20% smaller). Browser support is growing but not yet universal. WordPress 6.5+ supports AVIF uploads. For maximum compatibility, many sites serve WebP with AVIF as a progressive enhancement.
Legacy Image Formats
If your WordPress site still serves images exclusively in JPEG, PNG, or GIF format, you're likely sending more data than necessary. Converting to WebP can reduce your total page weight significantly — often by 30-50% for image-heavy pages.
How InspectWP Helps
InspectWP analyzes the images loaded on your WordPress site and detects whether you're using legacy formats (JPEG, PNG, GIF) instead of modern formats like WebP or AVIF. This helps you identify optimization opportunities for faster page loads.