How to Compress Images While Keeping Quality
Large image files slow down websites, bloat email attachments, and eat into storage limits — and in most cases, they're carrying far more data than the image actually needs for how it's going to be viewed. Compression fixes that, and done properly, the quality loss is barely noticeable.
Two different kinds of compression
Lossy compression discards some image data to shrink the file, controlled by a quality setting — more compression means smaller files but more visible artifacts if pushed too far. Lossless compression shrinks the file without discarding any visual data at all, by finding more efficient ways to store the exact same pixels — the savings are smaller, but there's genuinely zero quality tradeoff. Most everyday compression (for JPGs and WEBPs especially) uses the lossy approach, since it delivers much bigger size reductions.
Finding a quality setting that doesn't look compressed
Compression artifacts become genuinely visible mainly at low quality settings — blocky patches around sharp edges, color banding in smooth gradients like skies. At moderate-to-high quality settings (roughly 75–90% for JPG-style compression), the size reduction is substantial while artifacts stay essentially invisible at normal viewing sizes. The right setting depends on the image: a busy, detailed photo hides compression better than a smooth gradient or an image with large flat color areas.
Resizing first often helps more than compressing harder
If an image is going to be displayed at, say, 800 pixels wide on a website but the original file is 4000 pixels wide, no amount of compression setting-tweaking will be as effective as simply resizing the image down to something closer to its actual display size first. A smaller image compresses more efficiently at any given quality level, so pairing resize with compression usually gets a better result than compression alone.
Format matters as much as the compression setting
Compressing a photo that's saved as PNG will save less space than converting it to JPG or WEBP first and compressing that — PNG's lossless design just isn't built for photographic content the way JPG and WEBP are. If a PNG doesn't actually need transparency or pixel-perfect precision, converting format before compressing is often the bigger win.
Compress Image handles quality-based compression directly in your browser, letting you compare file sizes at different settings before downloading. If the image is also larger than it needs to be for its destination, Resize Image first will make compression more effective, and the image converter can switch formats if that's the bigger opportunity.