Blog image dimensions affect how images display across different devices, how fast your blog loads, and how Google indexes and ranks your content. Here are the ideal image sizes for blog posts in 2025.
Blog Image Size Recommendations 2025
| Image Type | Recommended Size | Aspect Ratio |
|---|---|---|
| Featured/header image | 1200×628 px | 1.91:1 |
| Inline blog images | 800×533 px | 3:2 |
| Wide full-width images | 1920×1080 px | 16:9 |
| Thumbnail | 400×250 px | 8:5 |
| Social share image | 1200×630 px | 1.91:1 |
Platform-Specific Featured Image Sizes
- WordPress: 1200×628px for featured images (matches social share preview)
- Ghost: 1200×675px (16:9) for featured post images
- Substack: 1200×628px for post thumbnails
- Medium: 1080×810px (4:3) or 1080×1080px (square) for cover images
File Size Guidelines for Blog Images
- Featured images: under 150KB (key for LCP Core Web Vital)
- Inline images: under 100KB each
- Full-width images: under 300KB
- All images: WebP format preferred over JPG for 30% smaller files
How to Prepare Blog Images
Upload your photo to imgresizr.com. Crop to the appropriate aspect ratio and resize to the recommended dimensions. Use the Compress tool to reduce file size. Convert to WebP for best performance. Download and upload to your blog platform — then fill in descriptive alt text in the media settings.
Prepare all blog images in the right size and format at imgresizr.com — free and instant.