Large images are the number one reason websites feel slow. A single 4 MB photo can add seconds to your page load time, hurt your Core Web Vitals score and push visitors away. The good news? You can shrink almost any image by 80–95% without anyone noticing the difference.
Why image size matters
- Speed: every 100 KB of images adds measurable load time on mobile connections.
- SEO: Google treats page speed as a ranking factor — smaller images rank better.
- Storage: compressed images use less bandwidth, which matters on shared hosting and CDN bills.
The best formats for the web
| Format | Best for | Notes |
|--------|----------|-------|
| WebP | Photos & graphics | Modern, tiny, supported everywhere in 2026 |
| JPEG | Photos | Great compression, no transparency |
| PNG | Logos & icons | Lossless, keeps transparency |
| SVG | Vector graphics | Infinitely scalable, tiny files |
How to compress without losing quality
- Start with the right format. Convert photos to WebP when possible — it's typically 25–35% smaller than JPEG at the same quality.
- Resize to the display size. If your page shows images at 800px wide, don't upload a 4000px photo. Resize first, then compress.
- Use a quality slider, not a preset. A quality of 75–85 usually looks identical to 100 but is dramatically smaller.
- Check transparency. For PNGs with transparency, keep PNG or use WebP — don't convert to JPEG (it fills transparency with black).