WebP vs JPEG
Both store photographs, but they make different trade-offs. Here is where they actually differ, and how to pick.
Short answer
WebP is a straight upgrade for web delivery — smaller at the same quality, plus transparency. JPEG remains the safer choice for files you hand to other people.
Why this comes up
This comparison usually shows up in a performance context: something told you your images are too heavy, and WebP is the first suggestion in every guide. It is good advice, but the size claim you have probably read — "25–34% smaller than JPEG" — comes from Google's own 2010 study and is optimistic against a well-tuned modern JPEG encoder. The real-world gain is closer to 15–25%, which is still worth having.
Side by side
| Property | WebP | JPEG |
|---|---|---|
| Compression | Lossy | Lossy |
| Transparency | Yes | No |
| Typical file size | 65-75% of an equivalent JPEG | 100% of an equivalent JPEG |
| Compatibility | Supported by all current browsers and most apps | Opens everywhere, including decades-old software |
| Usually comes from | Websites optimising page weight | Digital cameras and photo sharing |
What actually differs
Transparency is the decisive difference, not size
JPEG has no alpha channel and never will. Any image that needs to sit on a varying background — a product cut-out, a logo, a UI element — simply cannot be JPEG without baking in a background colour. Before WebP this forced you onto PNG and its file sizes. That substitution is where WebP's biggest practical wins come from, and they are far larger than 25%.
JPEG degrades every time you save it; WebP does too
Both are lossy, so neither is safe for an iterative editing workflow. This is worth saying because "upgrade to WebP" is sometimes read as "WebP fixes JPEG's problems". It fixes the size and the transparency; it does not fix generation loss. Keep a lossless master — PNG, TIFF, or the raw file — and treat both of these as delivery formats.
Universal versus merely wide support
JPEG opens in literally everything — every browser, every phone, every print kiosk, every piece of software written in the last thirty years. WebP is supported in all current browsers but is still not a format you can assume outside one: some desktop image viewers, older editing suites, and plenty of enterprise upload forms still reject it. For delivering to a browser this gap is irrelevant; for emailing a file to a client it is the whole story.
Which to use
Use WebP for
Images served from your own pages, especially anything currently stuck as PNG only because it needs transparency.
Use JPEG for
Files leaving your control — email, client hand-off, print, upload forms — and anywhere an unexpected format becomes a support conversation.