PNG to JPG — when it shrinks the file, and when it should stay PNG

"PNG files are not accepted." "File too large." Those are the two usual reasons to turn a PNG into a JPG. But converting is not always an improvement — it depends on what is in the picture.

PNG and JPG are good at different things

• JPG stores smooth, photographic images compactly by throwing away detail your eye barely notices.
• PNG throws nothing away. For images made of text, lines and flat colour — screenshots, charts, logos — PNG is sharper and often smaller. It can also keep a transparent background.

So a photo saved as PNG — common with screenshots of photos and some capture tools — shrinks dramatically as a JPG. A screenshot full of text, on the other hand, gets fuzzy edges around the letters and barely shrinks.

Converting several files

• Drop the PNG files into Bulk Image Resizer — as many as you like.
• Under Format, choose JPEG.
• Start with size on Keep original and quality at the default 0.80.
• Press Convert. Each file shows how much it shrank. Save them one by one or use Download as zip.

If a result came out larger than the original, the result line says why — usually it is the text-and-lines case above. Keep those as PNG.

Transparent backgrounds turn white

Convert a logo or icon with a transparent background to JPG and the transparent area is filled with white, because JPG has no transparency. That is fine on a white page; on a coloured background, keep it as PNG or choose WebP, which keeps transparency.

What about WebP instead?

If the place you are uploading to accepts WebP, it is the better choice: smaller than JPG at the same quality, and it keeps transparency. Some forms still only take JPG or PNG, so check first.

Open the Bulk Image Resizer