Heavy images are a common reason a website loads slowly, a mail server refuses an attachment, or sending a photo in a messaging app takes forever. The good news: most images can be compressed several times over with almost no visible loss of quality.
Why compression isn't just "lower the quality"
A plain quality slider in an editor is a blunt tool: it cuts into the entire image uniformly, without figuring out where the loss will be noticeable and where it won't. Specialized optimizers work smarter and are tailored to each format:
- JPG — optimized without visual loss by encoding the data already in the file more efficiently.
- PNG — compressed by reducing the number of colors in the palette in places where the eye won't notice the difference anyway (relevant for screenshots and flat-color graphics).
- GIF — optimized in a similar way, through palette and frame encoding.
- WebP — uses a more modern compression algorithm that's more efficient than JPG and PNG at the same visual quality.
That's why the image compression tool uses different utilities under the hood for different formats instead of one universal algorithm — the result is noticeably better than simply lowering a quality setting.
How much smaller will the file get
It depends on the source image, but typical figures are:
- Photos (JPG) — a 30-70% reduction with almost no visible quality loss.
- Screenshots and graphics (PNG) — often several times over, since these images contain few unique colors.
- WebP — usually the most compact option at comparable quality.
How to compress an image online
Upload the file to the compression tool, adjust the quality slider (80 by default — a good balance of size and result), and download the compressed version. The file format stays the same — JPG stays JPG, PNG stays PNG. Processing happens on the server, and the file is deleted right after processing.
When quality 80 isn't enough
If the difference after compressing at quality 80 still bothers you — for professional photography, say — try a higher value (90-95): compression will be lighter, but so will artifacts. For screenshots and web graphics, on the other hand, you can safely drop to 60-70 without losing readability.
If you also need to change the format
Compression preserves the original file format. If the task is not just to shrink the file but also to convert the image to a different format (say, PNG to JPG or to WebP), use the image converter — it lets you compress the result at the same time as changing the format.
Bottom line
Proper compression isn't about "lowering quality" — it's about removing redundant data the eye wouldn't notice anyway. A format-specific optimizer almost always produces a noticeably better result than a generic quality slider.