PNG vs JPG: five practical rules
Both formats are everywhere and both are old - JPG from 1992, PNG from 1996 - but they were built for opposite jobs.
Rule 1: photos go JPG
JPG uses lossy compression and is often a practical choice for photographs. File size and visible artifacts depend on the image and quality setting. Compare the exported image before choosing; there is no fixed JPG-to-PNG size ratio.
Rule 2: screenshots and text go PNG
JPG’s compression blurs sharp edges, and nothing has sharper edges than text on a screen. PNG is lossless: every pixel survives exactly. A screenshot saved as JPG gets a fuzzy halo around letters; as PNG it stays crisp.
Rule 3: need transparency? PNG
JPG has no alpha channel - it cannot store a transparent background. Logos, stickers, and cut-outs need PNG (or WebP or SVG).
Rule 4: editing masters go PNG
Repeated lossy JPG re-encoding can discard more detail. If you will edit and re-save an image several times, keep the working copy as PNG and export JPG once at the end.
Rule 5: websites increasingly go WebP
Google’s WebP (2010) does both jobs - lossy photos and lossless graphics, plus transparency - and can produce smaller files depending on the image and encoder settings. Major current browsers support it. Convert between any of these on this site: PNG to JPG, JPG to PNG, PNG to WebP.
Tested on this site
On 3 November 2026 we ran two synthetic 1600x1200 test images through this site's PNG to JPG converter. A photo-like image with fine grain (PNG 4,366,888 bytes) came out as a 737,100-byte JPG - about 6 times smaller at the same pixel count. A smooth gradient version (PNG 147,842 bytes) came out at 28,054 bytes. Grain was the only difference between the two, and it cost about 700 KB in the JPG: fine texture is exactly what JPG compresses worst. Both downloaded files decoded cleanly when we checked them.
Two synthetic images are not every picture. A flat screenshot with sharp text can come out larger as a JPG than as a PNG - that is Rule 2 above.