Every image format uses one or both. Understanding the difference helps you choose the right format every time.
Lossy compression reduces file size by permanently discarding data that humans are unlikely to notice. JPG is the most common lossy format. A JPG at quality 80 looks nearly identical to the original but can be 10-20x smaller. The trade-off: once data is discarded, it cannot be recovered. Re-saving a JPG multiple times causes progressive degradation, known as generation loss.
Lossless compression reduces file size without losing any data. The decompressed image is pixel-identical to the original. PNG is the most common lossless image format. Lossless files are larger than lossy equivalents, but they preserve every detail. You can edit and re-save a lossless image indefinitely without quality degradation.
| Aspect | Lossy | Lossless |
|---|---|---|
| File size | Much smaller | Larger |
| Quality | Slight loss (often invisible) | Perfect preservation |
| Re-editing | Degrades on each save | No degradation |
| Best for | Photos, web images | Graphics, logos, screenshots |
| Common formats | JPG, WebP (lossy mode) | PNG, WebP (lossless mode), TIFF |
Our Image Compressor uses smart lossy compression that keeps visual quality high while reducing file size. For format conversion, try PNG to JPG (lossless to lossy) or JPG to PNG (lossy to lossless container).
No. The quality already lost during JPG compression cannot be restored. Converting to PNG prevents further degradation but does not recover the original data. The file size will also increase.
For web images, quality 75-85 offers the best balance of file size and visual quality. Below 70, compression artifacts become noticeable. Above 90, file sizes increase rapidly with minimal visible improvement.
Yes. WebP and AVIF support both modes. You can encode a WebP as lossy for photos or lossless for graphics, making them versatile for mixed-content websites.