PNG vs JPG at a glance
- PNG — lossless (Deflate), 8-bit alpha transparency, up to 16 bits per colour channel. A browser canvas always writes 8 bits per channel.
- JPG — lossy (DCT), no transparency, 8 bits per channel, and accepted by practically every app, camera, printer and upload form.
PNG keeps every pixel exactly, which suits screenshots with text, logos and images you will edit again. JPG discards detail the eye rarely notices, which is why photographs shrink so dramatically.
When JPG makes the file smaller — and when it does not
In our tests with Chrome’s encoder, a 768×512 lossless photo saved as PNG (557,596 bytes) became 58,328 bytes as JPG at quality 85 — 89.5% smaller. A 1200×630 graphic with text and shapes dropped from 252,262 to 65,366 bytes, 74% smaller.
Small flat graphics are the exception. A 512×512 app icon with 21.7% transparent area grew from 16,311 to 18,026 bytes (10.5% larger) as JPG. When a result is not smaller, the row says so: keep the PNG, or use PNG to WebP instead.
What happens to transparent areas
JPG cannot store transparency, so every transparent or semi-transparent pixel has to become a solid colour. The canvas is filled with the background you choose (white by default) before the image is drawn, and after conversion each row reports how much of the image was actually transparent — or that nothing was, so the colour made no difference.
The black background that appears after some converters comes from encoding the image as if the alpha channel were not there: transparent pixels are stored as pure black. Pick the colour of the page or slide the image will sit on; a mismatched colour shows as a halo around smooth edges.
Choosing a quality
- Photos: 80–85. Quality 85 is the default on this page; in our tests quality 90 already made a re-saved JPG 6.8% larger than the original without visible gain.
- Screenshots and images with text: 90–92. JPG turns sharp edges into faint ripples, and red or blue text blurs most because colour is stored at half resolution (4:2:0 chroma subsampling).
- Quality 100 is rarely worth it: in our tests it produced files 3 to 7 times larger than quality 85 while restoring nothing.
Fuzzy text, colour shifts and large JPGs
- Text looks fuzzy or has halos: raise quality to 90 or more, or keep PNG for screenshots that are mostly text.
- Colours look slightly different: the browser converts to sRGB, so a PNG with a wide-gamut colour profile can lose a little saturation.
- The JPG is still too large: choose Max width (for example 1600 px) under Resize, or use the image compressor to reach a size target.
- Metadata: PNG files rarely carry EXIF. If yours does, it is removed by default.
Privacy and limits
Files are decoded and encoded by your own browser. Nothing is uploaded, and there is no daily limit or file count cap; files are processed one after another and can be downloaded one by one or as a ZIP.
Images larger than 4096 px on the long edge or 16 megapixels are scaled down to fit, and the row is marked when that happens. Animated PNG (APNG) files are converted from their first frame.