Convert WebP to JPG on Windows using PowerShell and WIC, no extra tools needed

Windows has included a built-in WebP decoder since version 1809 via the Microsoft WebP Image Extension, which PowerShell can access through the Windows Imaging Component to convert WebP files to JPG without installing third-party software. Simply renaming a .webp file to .jpg does not work, as the file's actual content remains WebP and validators or strict upload forms will reject it. A key caveat is that the Windows decoder flattens transparency to black before conversion, meaning images with alpha channels will lose transparency data regardless of output format. For files with transparency, using Python's Pillow library is recommended, as it reads the alpha channel correctly and allows compositing onto a chosen background color before saving. It is also worth noting that converting WebP to JPG re-encodes already-compressed data, typically resulting in a larger file with slightly reduced quality, so keeping the original WebP is advisable when file size matters.