How to Optimize Images for Your Website (Faster Loading, Better SEO)
Big images are the #1 cause of slow websites. Here's how to optimize your images — size, format and compression — so pages load fast and rank better.
Slow websites lose visitors and rank worse — and oversized images are the single biggest culprit. The good news: optimizing images is easy and free, and it can dramatically speed up your pages. This guide covers the three levers that matter — dimensions, format, and compression — and how to apply each.
Why image optimization matters
Images are usually the heaviest things on a web page. A single unoptimised photo can be several megabytes — larger than all your text and code combined. That means slower loads, higher bounce rates, and lower Core Web Vitals scores (which Google uses for ranking).
Optimising images often cuts page weight by 50–80% with no visible quality loss. It's the highest-leverage speed fix most sites can make.
Lever 1: right-size the dimensions
Don't display a 4000-pixel-wide photo in a 800-pixel-wide slot — the browser downloads all those extra pixels for nothing. Resize images to roughly the size they'll actually display (a little larger for high-density screens is fine, e.g. 1600px for a full-width image).
This alone can shrink a file enormously before you even compress it.
Lever 2: pick the right format
Photos → JPG or WebP. JPG is universal; WebP is ~25–35% smaller at the same quality and supported by all modern browsers.
Graphics, logos, screenshots, transparency → PNG or WebP.Icons → SVG where possible (tiny and infinitely scalable).
Using WebP for photos is one of the easiest big wins for page speed.
Lever 3: compress
After sizing and format, compress to trim the remaining fat. Target a sensible file size — often 100–300KB for content images — using a tool that lets you hit a size while keeping quality:
1. Open the compressor at sjpt.io.
2. Upload your (already resized) image.
3. Set a target size (e.g. 200KB).
4. Download and upload it to your site.
Do this for every image and your pages will feel dramatically faster.
Frequently asked questions
What size should website images be?Match the display size (e.g. ~1600px for full-width) and compress to roughly 100–300KB. Don't serve giant originals into small slots.
Which format is best for the web?WebP for photos (small + modern), JPG as a universal fallback, PNG/SVG for graphics, logos and transparency.
How much can optimization speed up my site?Often 50–80% less page weight from images alone, which noticeably improves load time and Core Web Vitals.
Is it free to optimize images?Yes — JPT AI's compress and convert tools are free with no watermark or sign-up.
Key takeaways
Optimise images in three steps: right-size the dimensions, pick an efficient format (WebP for photos), then compress to a sensible target. It's the biggest, easiest speed and SEO win for most sites — and it's free at sjpt.io. Compress Image Free →
