Run Video Speed Controller in Safari
Video Speed Controller, fine-grained speed control for any HTML5 video, has no official Safari version. Safari can't load Chrome
extensions: it uses its own native .appex format that must be built,
code-signed, and registered with macOS. Viaduct does all of that for you.
The whole process, three steps
- Get Viaduct. Free for your first 2 conversions, and it installs a small Safari extension that upgrades the Chrome Web Store.
- Open Video Speed Controller's Chrome Web Store page in Safari.
Video Speed Controller on the Chrome Web Store → - Click "Add to Safari." The store's "Add to Chrome" button becomes "Add to Safari." One click: Viaduct fetches Video Speed Controller, converts it to a native Safari extension, signs it, and installs it. It appears in Safari's toolbar like any native extension.
What's actually happening
Viaduct downloads the exact Video Speed Controller package published on the Chrome Web
Store (same code, same version) and rebuilds it as a native Safari Web Extension
(.appex). It handles the conversion, the code-signing, and the macOS
registration that normally require Xcode wrangling and a terminal. Because the result
runs inside Safari's own engine, you keep Safari's battery life. No second Chromium
process runs in the background.
Safari supports the same WebExtension API family that Chrome extensions are built on, so most extensions work as-is. Some Chrome-only APIs have no Safari equivalent, and Viaduct's built-in Analyze check tells you before you convert.
Questions
Is this the real Video Speed Controller, or a clone?
The real one. Viaduct converts the exact package its developers published on the Chrome Web Store. Nothing is modified, hosted, or redistributed; the conversion happens locally on your Mac.
Will it stop working after a week?
Free Apple accounts sign extensions for about 7 days. Viaduct Pro auto-re-signs converted extensions in the background before they lapse, so they never silently disappear.
What do I need?
macOS 13+. Node is bundled inside Viaduct, so there's nothing to install. Xcode is required (free, from the App Store) because Apple offers no other way to code-sign a Safari extension on a free account; Viaduct checks on first run and links the install if it's missing.
What does Viaduct cost?
Free for your first 2 conversions. Pro is $19 one-time: unlimited conversions plus auto-re-signing. The conversion engine is open source (MIT).
Video Speed Controller in Safari, two minutes from now.
Free for your first 2 conversions · Pro $19 one-time · macOS 13+
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