Why a WebP file fails a JPG-only form
WebP showed up as Chrome’s efficient image format and is now common on the public web. Right-click “Save image as” in a Chromium browser and you often get a .webp, even when the article you are reading looks like a JPEG. That file is fine in the browser. It is not fine in a lot of the software people still have to use: older Microsoft Office, some school portals, printer drivers, and CMS uploaders that whitelist image/jpeg and image/png only.
This page re-encodes a still WebP to JPEG (or PNG) in a worker, using the browser’s own decoder and canvas. Same privacy model as the HEIC to JPG converter: files stay on the device. Same limits: 50 files, 25 MB each, 200 MB total, 40 megapixels. Same ZIP path, STORE only, so JPEGs are not squeezed twice.
Lossy, lossless, and animation
WebP can be lossy (like JPEG) or lossless (like PNG). A second JPEG pass on an already-lossy WebP adds artifacts. Default quality 0.92 is meant for forms and email, not for archival. Pick PNG when the WebP was a screenshot or a graphic with type, or when a publisher wants a lossless still.
Animated WebP is a different object: a sequence of frames. This tool converts stills. If you drop an animation, the row is marked unsupported rather than silently exporting frame zero as if it were the whole file.
How the worker path differs from HEIC
HEIC often needs a WASM decoder (libheif) except on Safari, where native HEIC decode may already work. WebP decode is built into current Chrome, Firefox, Safari, and Edge, so this page usually never loads libheif. The island is the same component; only the accept list and copy change. WASM still will not load unless you somehow land a HEIC on this page, which the accept filter prevents.
EXIF in WebP, when present, is stripped by default. Check “Keep camera metadata” to copy an EXIF block into a JPEG output. GPS is part of that block; leave the box off if you are sending a photo to a form you do not control.
When to keep WebP
Keep WebP for the web. Convert when a human on the other end asked for JPG, when a printer queue rejects the extension, or when you are attaching to software that predates WebP. If the source was an iPhone photo, you want the HEIC converter, not this page. Step-by-step notes are in How to convert WebP to JPG.
Limits match the HEIC tool so you can learn them once: 50 files, 25 MB each, 200 MB total, 40 megapixels. JPEG default quality is 0.92. PNG is lossless. Metadata is stripped unless you check the box. The dropzone accepts paste, click, and drag. Conversion needs JavaScript; this article does not.