Published 2026-09-29
Save the same photo twice and you might get a 500KB file and a 5MB file. The difference almost always comes from the format. Knowing the basics of JPG, PNG and WebP takes most of the guesswork out of balancing quality and size.
The key to image formats is how they compress. Lossy compression discards detail the eye is unlikely to notice and makes files much smaller. Lossless compression keeps every pixel exactly as it was, at the cost of larger files. JPG is lossy, PNG is lossless, and WebP supports both.
JPG (JPEG) was designed for photographs with smooth color transitions. Saved at a reasonable quality it looks practically identical to the original while being a fraction of the size of a PNG. It also opens on virtually every device and service.
It does not support transparency, and sharp text or lines tend to pick up smudgy artifacts around their edges. Quality drops a little every time you save, so avoid repeatedly editing and re-saving the same JPG.
PNG is lossless and preserves every pixel. It is ideal for logos, icons, screenshots and text-heavy images with hard edges, and it supports transparent backgrounds.
Saving an ordinary photo as PNG, however, produces a file several times larger than JPG. Photos are full of tiny color variations that lossless compression cannot shrink well. If a photo does not need transparency, there is little reason to use PNG.
Google created WebP to make web pages load faster. At similar quality it is usually smaller than JPG, and it supports transparency and animation. All major browsers support WebP today and many websites serve their images in it.
Some older software and services still cannot upload or open WebP files. When sending files to other people or to a print shop, JPG or PNG is the safer choice.
| Situation | Format | Why |
|---|---|---|
| Everyday photos for social media | JPG | Small and universally compatible |
| Logos, transparent images | PNG | Transparency and crisp edges |
| Text-heavy screenshots, charts | PNG | No smudging around text |
| Images on your own blog or site | WebP | Smaller at the same quality |
| Sharing files, printing | JPG or PNG | Compatibility |
Converting a blurry JPG to PNG will not sharpen it. Lost detail does not come back, and the file just gets bigger. Going from PNG to JPG makes the file smaller but removes any transparency. Choose the format based on what the image is and where it will be used.
prezll saves in the same format you uploaded: JPG stays JPG, PNG stays PNG and WebP stays WebP. The editor shows the original size next to the estimated output size. If a photo is large because it is a PNG, simply reducing its width with the Resize tool can cut the size dramatically.
Open the image editor