David Baumwald

*** 2022-09-12 UPDATE *** 
@matt published a post and codified a final decision that <a href="https://make.wordpress.org/core/2022/09/11/webp-in-core-for-6-1/" rel="nofollow ugc">WebP by default would not be coming to WordPress Core in version 6.1</a>. That being the case, this plugin will not be necessary for users to prevent WebP generation by default as part of the Core upload process.
Proposed to be included in WordPress 6.0 is a new feature to generate and use webp images by default. Specifically, when an image is uploaded, a WebP version of every image subsize is created. According to <a href="https://make.wordpress.org/core/2022/03/28/enabling-webp-by-default/" rel="nofollow ugc">the proposal</a>, one downside is that generating WebP versions along with the original JPEGs will “use an additional ~70% of the storage space to store both file types.” Although this is hugely beneficial to most websites and, more importantly, their visitors, some site owners may not be immediately able to increase the size of their storage to accommodate the additional files. For more information, see the proposal or <a href="https://core.trac.wordpress.org/ticket/55443" rel="nofollow ugc">the Trac ticket</a>.
To help site owners manage the transition, this plugin adds a setting under Settings -> Media to either enable or disable WebP creation on the initial upload of JPEGs. For Multisite installations, the plugin can be activated network-wide or on individual sites.
*** 2022-07-22 UPDATE *** 
Although the original implementation was not merged in 6.0 due to community feedback, changeset 53751(https://core.trac.wordpress.org/changeset/53751) merged an updated implementation that addresses some(but not all) concerns from the community. This merge will be part of the 6.1 release, unless further changes are needed. Some site owners may not be able to immediately cope with doubling their required storage allotment with their host, so the original goal of this plugin remains. The code has been updated to disable WebP creation on upload globally. There is a new ticket discussing the possibility of making this feature into a setting(see https://core.trac.wordpress.org/ticket/56263). However, given WordPress’s core philosphy of “Decisions, Not Options”, it’s unlikely to proceed.

Disable WebP By Default

Thank you for creating this plugin!  It's a shame it's necessary, but I appreciate that you created it to make it easier for site owners to be able to take back control over their sites without needing to know how to add a filter.

Thank you!

Thank you for your work with this plugin (and just keeping track and reporting all the latest WEBP changes, etc.). Great to find so much useful information in the plugin documentation. Very much appreciated!

Thank you

A small plugin to control WebP image creation when JPEG images are uploaded.

yasuo3o3

andW Image Control extends WordPress image processing capabilities with comprehensive media management features.
Key Features:
<ul>
<li>Custom JPEG Quality: Set different JPEG quality levels for each image size</li>
<li>PNG to JPEG Conversion: Automatic conversion during upload with quality control</li>
<li>8 Custom Image Sizes: Pre-configured sizes (360px, 480px, 600px, 720px, 960px, 1200px, 1440px, 1920px)</li>
<li>Enhanced Media Library: MIME type labels and improved UI</li>
<li>Secure SVG Support: Upload SVG files with comprehensive security sanitization</li>
<li>WordPress Standards Compliance: Follows WordPress coding and security standards</li>
</ul>
This plugin is designed for developers and site administrators who need precise control over image processing and media management.
日本語説明:
andW Image Control は WordPress の画像処理を拡張するプラグインです。JPEG品質のカスタマイズ、PNG→JPEG自動変換、独自画像サイズ管理、SVG対応、メディアライブラリUI拡張を提供します。

andW Image Control

Advanced media control plugin with JPEG quality, PNG conversion, SVG safety, and custom image sizes.

Disable WebP By Default vs andW Image Control