Why WebP exists and why you keep running into it
WebP was introduced by Google in 2010 specifically to reduce the bandwidth cost of images on the web, using more modern compression techniques than JPG (borrowed from video codec research) to achieve meaningfully smaller files at equivalent visual quality — typically 25-35% smaller than JPG, and it supports both lossy and lossless modes plus transparency and animation in one format, which JPG can’t do at all. Because smaller images mean faster page loads (a factor in both user experience and search ranking), the vast majority of content management systems, e-commerce platforms, and image CDNs now serve WebP automatically to any browser that supports it, which is effectively all current browsers. This is why saving an image directly from a modern website frequently produces a .webp file even when you were looking at what appeared to be an ordinary photograph.
Where the compatibility gap still shows up
Browser support for WebP is now essentially universal, but authoring and print software support lagged much further behind and, in some cases, still hasn’t caught up. Photo printing labs and print shops frequently require JPG or TIFF specifically because their production pipelines were built around those formats. Some versions of Microsoft Office prior to relatively recent updates can’t insert WebP images directly. Certain older graphic design tools, embedded devices (some digital photo frames, older e-readers, point-of-sale systems), and specialized industry software never added a WebP decoder at all. If you’ve hit an error saying a file format isn’t supported, or an image simply won’t insert or preview somewhere, converting the WebP to JPG resolves it immediately because JPG decoding is close to universally implemented, even in decades-old software.
Lossy WebP vs. lossless WebP — why it matters for conversion
WebP actually supports two distinct compression modes that produce visually different starting points for conversion. Lossy WebP (the far more common case, especially for photos saved from websites) already discarded some detail during its own encoding, so converting it to JPG is a lossy-to-lossy step, similar in impact to re-saving an already-compressed JPG — the additional loss from a high-quality JPG re-encode is minor. Lossless WebP (less common, typically used for graphics, screenshots, or images where a tool specifically chose to preserve every pixel) is pixel-perfect against its source, and converting it to JPG is the one case here where you’re deliberately trading away losslessness for compatibility — worth doing only when you specifically need a JPG, not as a routine step.
What to expect after conversion
Because WebP’s compression is more efficient than JPG’s, a converted JPG will typically be somewhat larger than the source WebP for an equivalent look — this is expected, not a conversion problem, and is the direct cost of moving to a less efficient but far more universally supported format. If you’re converting purely for compatibility with one destination (a print shop, an older tool) but also plan to keep a web-facing copy, it’s worth keeping the original WebP for online use and treating the JPG as a compatibility-specific export rather than a full replacement.