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Stefan Van Damme Browser Extension & App Developer

Google Developer Expert in Web Technologies. Free browser extensions, apps, and games, used by more than 2 million people.

New on iPhone

Who's at the Door?

Knock. Peek. FLINCH. The free reaction game for iPhone, and the first built for iPhone Duo.

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Free Browser Extension

Turn Off the Lights™

Dim everything except the video. For Google Chrome, Firefox, Microsoft Edge, Opera, Naver Whale, Samsung Internet, and Apple Safari.

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Turn Off the Lights dimming a YouTube page so only the video player stays bright

Apps for every screen.

Handy tools and festive favorites for Windows, Mac and iPhone.

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Widgets for Windows 11.

CPU, memory, disk and more, right on your desktop.

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CPU Check widget for Windows 11

Google Developer Expert.

Web Technologies. Recognized by Google since 2023.

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45K on YouTube.

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About Stefan Van Damme

Stefan Van Damme is a Belgian software developer and Google Developer Expert in Web Technologies, specializing in browser extension development. He is the creator of Turn Off the Lights, a free and Open-Source extension for Google Chrome, Firefox, Microsoft Edge, Opera and Apple Safari that dims web pages and highlights the video player, with features like Dark Mode, YouTube AutoHD and Mouse Volume Scroll.

Next to his extensions, Stefan builds Windows and Mac apps such as Aurora Player, Finance Toolbar and GPU Check, widgets for Windows 11, and the free iPhone game Who's at the Door?. On his blog and YouTube channel he shares tutorials on Manifest V3, the WebExtensions API and getting the most out of his apps. Questions? Visit the support page or read more about Stefan.

Frequently asked questions.

Who is Stefan Van Damme?

Stefan Van Damme is a Belgian software developer and Google Developer Expert in Web Technologies since 2023. He has built the Turn Off the Lights browser extension since 2009, and also makes Windows and Mac apps, Windows 11 widgets and Who's at the Door?, a free game for iPhone.

Is Turn Off the Lights free?

Yes. Turn Off the Lights is free and Open Source under the GNU General Public License v2. It is available for Google Chrome, Firefox, Microsoft Edge, Opera, Naver Whale, Samsung Internet and Apple Safari, and is translated into 55 languages.

How many people use Turn Off the Lights?

More than 2 million people use Turn Off the Lights. In October 2026 the Chrome Web Store showed 1,900,000+ weekly users, Microsoft Edge Add-ons about 372,000 active installs and Firefox Add-ons about 67,000 daily users. On Chrome it is rated 4.3 out of 5 from about 33,500 ratings.

Does Turn Off the Lights collect personal data?

No. The extension does not collect personal data, as declared on its Firefox Add-ons listing, and its full source code is public on GitHub.

What is Who's at the Door?

Who's at the Door? is a free knock knock reaction game for iPhone and the foldable iPhone Duo. You peek at the caller and close the door on villains before they pounce. Your score is your FLINCH time in milliseconds, with a daily challenge and Game Center leaderboards. Discover more about Who's at the Door?