Video Speed Controller vs Video Speedifier

A Safari port version of an MIT open source Chrome extension(https://github.com/igrigorik/videospeed) for controlling the video speed of any video in a website. And the app is also open source in https://github.com/Kyle-Ye/Video-Speed-Controller

Take control of every video you watch. Video Speedifier is a clean, powerful Safari extension that lets you adjust playback speed on any website with precision and ease. Use the smooth slider for fine-grained control (0.1× increments) or tap the quick preset buttons for common speeds. Turn on Overdrive when you want to push speeds even higher. It works across YouTube, Netflix, online courses, Twitch, and most other video players — including tricky ones that try to reset the speed. Key Features • Precise speed control from 0.1× up to 5× • Customizable preset buttons • Overdrive mode for faster playback • Works on iPhone, iPad, and Mac • Clean, modern interface built with SwiftUI • Intelligent handling of dynamic and embedded videos Getting started is simple: install the app, enable Video Speedifier in Safari’s Extensions settings, and you’re ready to go. The extension then appears in your toolbar whenever you need it. Whether you’re speeding through lectures, slowing down language content, or just want to watch at your own pace, Video Speedifier gives you full control without leaving the page.