Technical Reference
SEO Image Size:
Dimensions, File Sizes & Formats
Wrong image sizes hurt your Core Web Vitals, slow your pages, and reduce your Google Images rankings. This guide gives you the exact dimensions, file sizes, and formats for every image use case — with the SEO reasoning behind each recommendation.
Why Image Size Matters for SEO
Image size affects SEO through two confirmed Google ranking factors. Largest Contentful Paint (LCP) measures how quickly the largest visible element loads — usually a hero image. Images over 200KB are the leading cause of poor LCP scores. Cumulative Layout Shift (CLS) is caused by images without declared width and height attributes that shift the page layout as they load.
Beyond Core Web Vitals, image dimensions affect how images display in Google Images search results. Images with standard aspect ratios (1:1, 4:3, 16:9, 1.91:1) are displayed more prominently in image carousels and rich results. Non-standard dimensions are often cropped or displayed at reduced size.
For the full technical implementation of width and height attributes, see our guide on SEO image width and height. For the broader optimization context, read our image SEO optimization guide.
SEO Image Size Reference Table
| Use Case | Width | Height | File Size | Format | Notes |
|---|---|---|---|---|---|
| Hero / Banner | 1200–1920px | 400–800px | < 200KB | WebP / JPEG | Use eager loading; this is usually the LCP element |
| Blog / Article | 1200px | 628px | < 150KB | WebP / JPEG | 1.91:1 ratio also works for Open Graph sharing |
| Product Image | 1000–2000px | 1000–2000px | < 300KB | WebP / JPEG | Square (1:1) preferred for e-commerce grids |
| Thumbnail / Card | 400–600px | 300–400px | < 60KB | WebP | Use lazy loading; serve via srcset |
| Logo | 200–400px | 60–120px | < 20KB | SVG / PNG | SVG preferred; PNG fallback for EXIF injection |
| Google Business Profile Cover | 1080px | 608px | 10KB–5MB | JPEG / PNG | 16:9 ratio; minimum 480×270px |
| Google Business Profile Photo | 720px+ | 720px+ | 10KB–5MB | JPEG / PNG | 1:1 ratio recommended |
| Open Graph / Social Share | 1200px | 630px | < 1MB | JPEG / PNG | 1.91:1 ratio; minimum 600×315px |
WebP vs JPEG: File Size Comparison
WebP delivers roughly 25–35% smaller file sizes than equivalent JPEG at the same visual quality. For a 1200×628px blog image, a JPEG at 85% quality might be 180KB. The same image as WebP at 80% quality is typically 110–130KB. Over a page with 10 images, that difference is 500KB+ of savings — directly improving LCP.
Browser support for WebP is now at 97%+ globally. There is no longer a meaningful reason to serve JPEG for photographs on the web, except for images that need EXIF metadata preserved (some WebP encoders strip EXIF). For EXIF-hardened images, JPEG remains the safest choice for metadata preservation.
LinkDaddy Media processes images as JPEG to ensure EXIF metadata is preserved through the hardening pipeline. The output files are optimised to 88% quality, which delivers excellent visual results at file sizes typically under 200KB for standard business photography.
Automate Image Size Optimization
LinkDaddy Media automatically resizes, compresses, and optimises every image you upload — then injects EXIF metadata and generates ImageObject schema. No manual work required.
Frequently Asked Questions
What is the best image size for SEO?
For website images, keep file size under 200KB and use dimensions appropriate to the display size. Hero images: 1200–1920px wide. Blog images: 1200×628px. Product images: at least 1000×1000px. Always declare width and height attributes in HTML.
What is the maximum image file size for SEO?
There is no hard maximum, but images over 200KB significantly slow page load times and hurt Core Web Vitals LCP scores. Google recommends images under 100KB where possible. Use WebP format and compression to achieve this.
What image size does Google Business Profile require?
Google Business Profile recommends images between 10KB and 5MB, minimum 720×720px. Cover photos: 1080×608px. Profile photos: 250×250px minimum. Ideal aspect ratio: 4:3 or 1:1.
Does image size affect SEO rankings?
Yes. Large image file sizes slow page load times, directly affecting Core Web Vitals LCP scores — a confirmed Google ranking factor. Images without declared width and height cause CLS, another ranking factor.