How PNG differs from JPG
PNG uses lossless compression. It looks for patterns and repetitions and stores them compactly, but it never throws anything away, so what comes out is pixel for pixel identical to what went in. That makes it ideal for logos, screenshots, diagrams and anything with sharp edges.
The same property makes it inefficient for photographs. A photo has almost no exact repetition, so there is little for the format to compact, and the file stays large. This is why a photo saved as PNG can be many times the size of the same photo as a JPG.
What compression means for a PNG
Because no data can be discarded, there is no quality slider to turn down. The only lever is resolution. Reducing a PNG from 2000 pixels wide to 1000 removes three quarters of the pixels and cuts the file roughly in proportion, while the remaining pixels stay perfectly accurate.
In practice this works well, because most PNGs are far larger than the space they are displayed in. A logo shown at 200 pixels does not need to be stored at 2000.
When to convert instead
- Photographs. If there is no transparency, convert to JPG. The reduction is dramatic and the quality loss is invisible at normal sizes.
- Form uploads. Most Indian portals expect JPG. Convert before uploading rather than fighting the PNG size limit.
- Website images. WebP handles both transparency and photographs, and produces smaller files than either PNG or JPG.
- Logos and icons. Keep PNG. Sharp edges and transparency are exactly what it is good at.
Frequently asked questions
Why is a PNG so much larger than a JPG of the same photo?
PNG is lossless, meaning it stores every pixel exactly as it was. JPG discards detail your eye is unlikely to notice. For a photograph that difference can be ten times the file size or more.
Does compressing a PNG keep the transparent background?
Yes. The output stays a PNG with its alpha channel intact, so logos and cut out images keep their transparent edges.
How can a lossless format be compressed at all?
By reducing the pixel dimensions. Since the data itself cannot be thrown away, a smaller PNG means fewer pixels. The tool searches for the largest dimensions that fit under your target.
My PNG barely got smaller. Why?
PNG files that are already small or already optimised leave little room. If the image is a photograph and you do not need transparency, converting it to JPG will reduce the size far more effectively.
Is PNG the right format for a screenshot?
Usually yes. Screenshots contain sharp text and flat colour, which PNG stores cleanly and JPG blurs. Keep screenshots as PNG unless file size is the overriding concern.
Will the image look blurry after compression?
Not blurry in the JPG sense, since no detail is discarded within a pixel. What changes is the resolution, so a heavily reduced PNG has fewer pixels and looks softer when viewed at its original size.