It does not seem to work as expected. Uploading JPEG (or PNG) as product images seems to result in JPEG (or PNG) in frontend. Other images are translated to WebP correctly.

Here is the behavior you can expect from Odoo regarding image conversion to WebP :

Version 17

• When you upload an image through the website, it is automatically converted to WebP format.
• When you upload a product image via the website, it is also automatically converted to WebP.
• However, if you upload a product image from the Odoo back-end, it is not converted to WebP format.

Version 18

• Uploading an image through the website automatically converts it to WebP.
• Product images uploaded via the website are also converted to WebP automatically.
• Product images uploaded through the Odoo back-end are converted to WebP.
• However, images imported via an Excel or CSV file are not converted to WebP.

General Note

Images already stored in your Odoo database prior to upgrading to Version 17 or 18 will not be converted to WebP format automatically.

If you want to convert existing product images to WebP, you’ll need to handle the conversion outside Odoo and then re-import them into Odoo.