The short version
JPEG is a lossy format, good for photos, small files, no transparency. PNG is lossless, supports transparency, better for graphics, screenshots and logos, but produces larger files for photos. WebP supports both lossy and lossless compression and transparency in one format, and at a given visual quality it typically produces smaller files than either JPEG or PNG.
Why WebP usually wins on file size
WebP uses newer compression techniques than JPEG (from 1992) or PNG (from 1996), so it squeezes more out of the same visual quality. That matters most for websites, since smaller images mean faster page loads. Browser support for WebP is now effectively universal across current browsers.
When PNG or JPEG still make sense
PNG stays the safer choice when a tool or workflow outside your control doesn't accept WebP, some older software and some print pipelines still expect PNG or TIFF. JPEG remains fine for photos where file size isn't critical and you want the widest possible compatibility with very old software.
AVIF, a newer format still, can compress even further than WebP in many cases, at the cost of slower encoding and slightly less universal support.
Convert between all of these on your Mac
FlexiWebP batch-converts PNG, JPEG and HEIC to WebP and AVIF, with a quality preview before you export.
Scan with your iPhone to install FlexiWebP
View on the App StoreFrequently asked questions
Do all browsers support WebP now?
Yes, all current major browsers display WebP images natively.
Is WebP always smaller than JPEG?
Usually, but not always, it depends on the image content and the quality setting used for each. In most real-world cases WebP comes out smaller at comparable quality.
Can WebP replace PNG for logos with transparency?
Yes, WebP supports transparency in both its lossy and lossless modes, so it can replace PNG for most graphics.