WebP vs PNG: which should you use?

The short answer

Use WebP for images that ship on a website, because it is smaller than PNG at equivalent quality and every modern browser can display it. Use PNG when a file needs to work everywhere without question, such as inside design software, older CMSs, or documents, or when you specifically need a format that has been stable and universally readable for decades.

What PNG actually is

PNG (Portable Network Graphics) was created in 1996 as a free, patent-unencumbered replacement for GIF. It stores pixels losslessly using DEFLATE compression, the same general-purpose algorithm behind zip files, which means a PNG decodes back to the exact pixels that were encoded. It also supports a full 8-bit alpha channel, so a logo or icon keeps clean, soft edges over any background.

That losslessness is also PNG's weak point: it compresses smooth photographic gradients poorly compared to formats designed around human vision, so a photo saved as PNG is often several times larger than the same photo saved as JPG or WebP.

What WebP actually is

WebP is a format Google introduced in 2010, built to replace both JPG and PNG on the web. It supports two distinct modes: a lossy mode based on the VP8 video keyframe codec, and a separate lossless mode. According to Google's own compression studies, WebP's lossless mode produces files about 26 percent smaller than PNG at equivalent quality, while WebP's lossy mode produces files roughly 25 to 34 percent smaller than comparable JPEG images. WebP's lossless mode also supports a full alpha channel, so it is a direct drop-in replacement for transparent PNGs, just smaller.

Browser support is no longer a real obstacle. Every major browser, Chrome, Firefox, Safari and Edge, has supported WebP for several years. The places WebP still runs into friction are older image editors, some legacy content systems, and certain print or design workflows that expect PNG or TIFF specifically.

Transparency compared

Both formats handle transparency well. PNG's alpha channel is the format most people default to for logos and UI assets, and it remains the safest choice when a file has to open correctly in software you do not control. WebP's lossless alpha channel is functionally equivalent in quality and compresses more efficiently, so once you know the target environment supports WebP, there is no transparency-related reason to prefer PNG over it.

When to actually pick PNG over WebP

Choose PNG when a downstream tool cannot open WebP: some older versions of design and office software, some print pipelines, and some upload forms still reject it outright. Choose PNG for screenshots and diagrams you plan to keep editing in raster software that treats PNG as its default lossless format. Outside of those cases, WebP is the better default for anything destined for the web.

Does converting PNG to WebP lose any quality?

Not if you use WebP's lossless mode, which decodes back to the exact same pixels as the source PNG, just in a smaller file. WebP's lossy mode does discard some data in exchange for an even smaller file, similar to how JPEG works.

Can I still open a WebP file in older software?

Most current image viewers and browsers open WebP natively. Some older desktop editors and legacy tools do not, which is the main reason people still convert WebP back to PNG or JPG.

Is WebP always smaller than PNG?

For the vast majority of images, yes, particularly photographs and images with gradients. A handful of very simple, flat-color graphics can occasionally compress about the same in either format.