Your website looks great in design — clean photos, sharp product shots, professional graphics. Then you check it on mobile or run it through Google PageSpeed Insights and the result is brutal: the homepage takes 6 seconds to load, and image files are blamed for most of it.
Images typically account for 50–70% of the total weight of a modern web page. Compressing them properly is the single most impactful performance win you can make — and you do not need expensive software to do it.
When a visitor opens your site, their browser downloads every image on the page. Each megabyte takes a measurable amount of time:
If your homepage contains 10 product photos at 2 MB each, that is 20 MB before a single line of text loads. On mobile, that translates to 20 seconds of waiting — and most visitors abandon a page that takes longer than 3 seconds to become usable.
Google uses Core Web Vitals as a direct ranking signal. Largest Contentful Paint (LCP), the metric measuring when the main content appears, is heavily affected by image weight. A site with 200 KB hero images consistently outranks an equivalent site serving 2 MB hero images, all else being equal.
JPG is the default for photographs and complex images with many colours and gradients. Lossy compression is invisible at quality levels above 80%. Universally supported on every browser and device.
PNG is for graphics that need transparency or sharp edges — logos, icons, screenshots, illustrations with flat colours. PNG uses lossless compression, so files are larger than JPG for the same image, but quality is preserved exactly.
WebP is the modern format from Google. It typically produces files 25–35% smaller than JPG at the same visual quality, supports both lossy and lossless modes, and handles transparency. Supported by all current browsers.
In practice: use WebP for photos and complex images, PNG when you need transparency that older devices must support, and JPG only when you need maximum compatibility with very old systems. For images that don't need transparency, our PNG to JPG converter can give you immediate 60–80% size savings.
For web use, quality settings in the 75–85 range deliver excellent visual results with significant size reductions. Drop to 70 for thumbnails or images appearing at small sizes. Stay at 90+ only for hero images where every pixel will be inspected.
Real-world reductions you can expect:
Test on the actual page where the image will appear, not in isolation. An image looks different at 1200px wide on a hero banner versus 300px wide on a product grid. Set the quality such that the image looks correct in its real context.
A typical homepage's worth of images takes under a minute to compress. Your images never leave your browser, so even confidential product shots stay completely private.
Will compression reduce my image dimensions?
No. Compression reduces file size without changing dimensions. The image stays 1200×800 (or whatever size you uploaded) — only the file weight changes.
How much will my page speed improve?
For most pages, compressing images cuts total page weight by 60–80%. Largest Contentful Paint typically improves by 1–3 seconds on mobile. Pages often go from "Poor" to "Good" on Core Web Vitals.
Should I serve different image sizes for mobile vs desktop?
Yes, where possible. Use the HTML srcset attribute or modern CMS features to serve a 600px image to mobile users instead of the full 1500px desktop version. Compression and responsive images work together — both matter.
Can I compress PNG files without losing transparency?
Yes. PNG compression is lossless and transparency is preserved. If you need both transparency and smaller files, convert to WebP — it supports transparency at much smaller file sizes than PNG.
Use our free Image Compressor tool — works in your browser, nothing to install.
Image Compressor — Free