How Image Compression Improves Website Speed & Core Web Vitals

Images are often the largest assets on a webpage. Compressing images correctly can dramatically improve website speed and Core Web Vitals.

What is image compression?

Image compression reduces the file size of images by optimizing how image data is stored. Smaller image files load faster without visibly reducing image quality.

How images affect website speed

Uncompressed images increase page size, slow down loading times, and consume more bandwidth — especially on mobile devices.

• Longer time to first load
• Higher bounce rates
• Poor mobile performance
• Lower conversion rates

Image compression and Core Web Vitals

Google’s Core Web Vitals measure real-world user experience. Image optimization plays a major role in these metrics.

• LCP (Largest Contentful Paint): Smaller images load faster
• CLS (Cumulative Layout Shift): Properly sized images prevent layout shifts
• INP: Reduced image load improves interaction performance

Why Google cares about image compression

Google prioritizes fast-loading websites. Image-heavy pages with poor optimization often fail performance benchmarks, reducing search visibility and rankings.

How to compress images for better performance

1. Resize images to their display size
2. Choose the right image format (PNG or JPG)
3. Apply lossless or smart lossy compression
4. Use lazy loading for below-the-fold images
5. Compress images before upload

Example: Image compression impact

Compressing a 1.5MB image to 200KB can reduce page load time by several seconds, especially on mobile networks.

Best tools for image compression

Browser-based tools allow you to compress images securely without uploading files to a server.

Improve website speed with image compression

Optimize your images instantly using our fast, secure, and free image compression tools.