How to Compress Images for a Faster Website
You ran your site through a speed test and the report is a wall of warnings about “properly sized images” and “efficient image formats.” It is not a coincidence — on most websites, images are the single heaviest thing visitors download. Compress them well and almost every speed problem improves at once. Here is how to do it for free.
How to compress your website images with QuickWand
QuickWand's free image compressor works entirely in your browser, so you can process a whole site's worth of images privately and quickly.
- Open the Image Compressor and drag in all the images you want to optimize at once.
- Set Quality to 80–85% and use the live size estimate to confirm each image lands under your target.
- Switch on Resize → Max size and cap dimensions to the largest size your layout actually displays — there is no point serving a 4000 px image into a 1200 px column.
- Click Download all (.zip) and replace the originals on your site.
Why image weight is the bottleneck
Google's Core Web Vitals put a number on real-world speed. The headline metric, Largest Contentful Paint (LCP), measures how long the biggest visible element takes to load — and on content-heavy sites that is nearly always an image. Google rates LCP as “good” at 2.5 seconds or less, “needs improvement” from 2.5 to 4.0 seconds, and “poor” beyond 4.0 seconds. Heavy images are the fastest way to fail that threshold and the fastest way to fix it.
The knock-on effects are real money: faster pages keep visitors engaged, reduce bounce, and rank better in search. A lighter site is a better site on almost every axis that matters.
Recommended targets and format tips
- Content images: under 150–200 KB.
- Thumbnails: under 100 KB.
- Hero / full-width banners: up to about 300–400 KB.
- Format: WebP for the smallest files (universally supported in modern browsers); JPG for compatibility; PNG only for logos, icons, and transparency.
If some of your source files are PNG photos, convert them with the PNG to JPG converter before compressing — PNG is a poor format for photographs and bloats your page weight. And if you have stray WebP files that won't open in your editor, the WebP to JPG converter converts them instantly.