Your blog's hero image is almost certainly the LCP element — the metric Google cares about most for rankings. Switching from JPG to WebP cuts image weight 25–35%, improving load times and Core Web Vitals scores without changing visual quality.
Drop your JPG hero and in-post images. Convert. Upload to your blog.
| Image Type | Recommended Size | Target File Size (WebP) | Notes |
|---|---|---|---|
| Hero / Featured image | 1200 × 630 px | Under 120 KB | og:image standard — used by all social platforms |
| In-post content images | 800 px wide | Under 80 KB | Keep height proportional; add loading="lazy" |
| Infographics | 800 × 1200 px | Under 200 KB | Tall format ranks better in Google Image Search |
| Author headshot | 200 × 200 px | Under 20 KB | Use WebP or PNG; often displayed at 48–80px |
| og:image (social share) | 1200 × 630 px | — | Keep as JPG for og:image; use WebP for the <img> tag |
Upload WebP directly to Media Library. Generates all thumbnails automatically.
Ghost CDN accepts and serves WebP. Drag into post editor directly.
Upload WebP in Assets panel. Webflow's CDN serves it to all modern browsers.
Medium's CDN converts all uploads to WebP automatically. No action needed.
Upload WebP directly. Substack serves it via their CDN to subscribers.
Squarespace auto-converts uploaded images to WebP via their CDN (Squarespace 7.1+).
Resize your hero to 1200×630 px and in-post images to 800 px wide. Don't upload oversized originals — that wastes storage and conversion time.
Drop all blog post images into Convertlo. Enable batch mode, set quality to 85, convert all at once.
Rename: how-to-bake-sourdough-starter.webp. Google Image Search indexes filenames as a ranking signal.
Upload to your blog platform. Add descriptive alt text to every image — it's both an accessibility requirement and an SEO signal.
In most blog posts, the hero/featured image is the Largest Contentful Paint element. Cut its file size with WebP and add fetchpriority="high" to tell the browser to load it first.
Add loading="lazy" to every in-post image. Do NOT add it to the hero — that delays the LCP element and hurts your score.
Before uploading, rename images to describe the content: sourdough-starter-day3.webp. Google reads filenames as context for image ranking.
Write alt text that describes what's in the image, not keyword stuffing. "A sourdough starter in a glass jar on a wooden counter" beats "sourdough bread recipe blog post."
Use WebP for <img> tags in your post. Set your og:image meta tag to a JPG — Twitter, LinkedIn, and some Slack versions prefer JPG for link preview images.
A WebP at quality 80–85 typically reaches under 100 KB for a 800 px wide image. If it's still over 150 KB, run it through Convertlo's compressor after converting.