What is WebP?
Definition
WebP is an image format built for the web. It can compress lossy or lossless, and it supports transparency, so one format can replace both JPEG and PNG in many cases. It is supported by current browsers.
Why it matters for sellers
Shop platforms often serve WebP to speed up pages, and some CMS or theme settings ask for it directly. A smaller image can help a product gallery load faster on mobile.
WebP is not accepted everywhere. Some marketplaces, email clients and older software still expect JPG or PNG, and a download saved as WebP can be a surprise. Knowing how to convert in both directions avoids rejected uploads.
How to do it with Instasize
Instasize converts between JPG, PNG, WebP and AVIF in your browser, so you can make a WebP or turn one back into a common format.
- Open the Image Converter and upload your image.
- Choose WebP, or JPG or PNG if you need to convert one back.
- Adjust the output quality and compare file sizes.
- Download the converted image.
Related Instasize pages
Examples
Shop theme requests WebP
A store setting asks for WebP uploads. The seller converts product JPGs and checks the new file sizes before uploading.
Download will not upload
A saved image arrives as WebP and a marketplace form rejects it. Converting it to JPG fixes the upload.
Cutout with transparency
A product cutout needs a transparent background but a smaller file than a PNG. WebP can keep the transparency.
Frequently asked questions
Is WebP better than JPEG?
WebP can give smaller files at similar quality, but results vary by image and settings. It does not always beat a well-tuned JPEG, and JPEG is accepted in more places.
Does WebP support transparency?
Yes. WebP supports transparent pixels in both its lossy and lossless modes.
Can every marketplace use WebP?
No. Check the marketplace's current image policy. If it lists only JPG or PNG, convert before you upload.
Is WebP lossy or lossless?
Both. It has a lossy mode and a lossless mode. The setting you choose when exporting decides which one you get.