How to Compress Images Without Losing Quality
"Losing quality" is where most compression advice goes vague, because the honest answer is that JPEG compression always discards some data — the real skill is discarding data your eyes won't miss.
How JPEG compression actually works
JPEG uses "lossy" compression, meaning it permanently removes some image information to shrink file size. It does this cleverly, though: it exploits the fact that the human eye is far more sensitive to brightness changes than to subtle color changes, so it compresses color detail more aggressively than brightness detail. At moderate compression levels, this trade-off is nearly invisible; push it too far and you start seeing blocky artifacts, especially around sharp edges and text.
Choosing a quality setting
| Quality range | Best for |
|---|---|
| 90–100% | Print, photography portfolios, archival copies |
| 75–90% | Website hero images, product photography |
| 50–75% | Blog images, thumbnails, background images |
| Below 50% | Rarely worth it — visible artifacts usually outweigh the size savings |
A useful habit: compress at 80% first, view the result at actual size, and only drop lower if the file size still isn't small enough. Going straight to a low number "to be safe" usually costs more visual quality than necessary.
When to use PNG instead
PNG uses lossless compression — no image data is discarded — which makes it the better choice for screenshots, logos, icons, and any image with flat colors, sharp text, or transparency. The trade-off is file size: a photograph saved as PNG is often several times larger than an equivalent JPEG, because photographic gradients don't compress well without loss.
A simple rule of thumb
Photographs → JPEG. Graphics, logos, and anything needing transparency → PNG. If you're unsure, compress a JPEG version and compare the file size against a PNG version of the same image; whichever gets you an acceptable size at acceptable quality wins.
Frequently asked questions
75–85% is a strong starting point for most web images — it typically cuts file size significantly with little to no visible quality loss.
No — JPEG compression is lossy and irreversible, so always keep an original, uncompressed copy before compressing for web use.
Conclusion
Good compression isn't about finding the smallest possible file — it's finding the smallest file that still looks right at the size it will actually be displayed. Start around 80% quality, compare visually, and adjust from there.
Try it with the Image Compressor.