Dont Accept imagewebp is a Firefox extension designed for users who prefer JPEG and PNG image formats over WebP and AVIF formats. This subscription-based tool modifies the Accept header in web requests, prompting websites to deliver images in more commonly used formats. With the added features of exempting specific sites, such as Patreon, and automatically exempting Reddit images when using compatible extensions, it enhances user experience by ensuring compatibility with various image sources.

The extension operates by utilizing the onBeforeSendHeaders API to monitor and edit request headers, although it requires broad permissions for this functionality. Users may encounter conflicts with other extensions that also manipulate the Accept header, leading to potential inconsistencies. The latest version addresses these conflicts and offers a straightforward solution for Firefox users who cannot edit the network preferences directly.