About Previews and the Developer Behind It
Previews is built and maintained by one independent developer. It has been going since February 2020, it is used by more than 60,000 people, and it collects nothing about any of them. This page covers who makes it, how it is built, and what it does with your data.
Who makes Previews?
Previews is made by MarkM, an independent developer working alone. There is no company behind it, no team, and no investors. Every feature in the extension was written, tested and shipped by one person, and most of them exist because a user asked for them.
That has an upside and a downside worth being honest about. The upside is that feature requests go straight to the person who can implement them, and bugs get fixed without passing through a support queue. The downside is that everything moves at the pace one person can manage.
How long has Previews been around?
Since February 2020, which is more than six years of continuous maintenance. That covers several major Twitch redesigns, YouTube's move to its current player, and Kick launching and being added as a supported platform.
Longevity matters more for browser extensions than for most software. Streaming sites change their markup constantly, and an extension that is not actively maintained breaks within months. A six-year-old extension that still works is evidence of ongoing work rather than a single release.
How many people use it?
More than 60,000 active users across Chrome, Firefox, Edge and other Chromium browsers, with a 4.8 out of 5 rating on the Chrome Web Store. Previews has also been Featured by the Chrome Web Store and recommended by Mozilla's add-on team.
Dexerto called it a "genius Twitch extension" for bringing YouTube and Facebook streamers into the Twitch sidebar. Mozilla's add-ons blog featured it in its roundup of extensions for customising Twitch.
What does Previews do with your data?
Nothing. Previews does not collect, store or sell user data. Your settings and favourites live in your own browser, and the optional cloud sync stores only what you choose to sync so it can reach your other devices.
One feature deserves a specific note, because it is the one that sounds like it would need your data. Link Previews in Chat fetches link previews through Previews' own servers rather than from your browser, which means the site behind a link never sees your IP address. The proxying exists to take your address out of the request, not to put it in ours.
The full details are in the privacy policy.
How is Previews built?
It is a browser extension written in JavaScript, running on Chrome, Firefox, Edge, Brave and Opera from a single shared codebase. Each of the 60 plus features is an independent toggle, so nothing is all or nothing and turning something off returns the platform to its normal behaviour.
Supporting three streaming platforms from one codebase is most of the work. Twitch, YouTube and Kick each structure their pages differently and change them without notice, so a feature like hover previews is really three implementations behind one switch. That is also why some features are available on one platform and not another: where a platform already does something well, Previews leaves it alone rather than duplicating it.
What is in the extension?
More than 60 separate features, grouped in the settings panel by what they affect: hover previews, player controls, the sidebar, chat, raids and predictions. The ones people search for most have their own pages explaining what they do and how to enable them.
Browse all Previews features for the full list, or start with the ones most people turn on first: Sidebar Previews, Sidebar Favorites, Picture-in-Picture and Multi-Stream.
Getting in touch
Feature requests and bug reports go directly to the developer. Use the mail icon in the top bar of this page to get the contact address. Every message goes to the same inbox, and there is no support tier between you and the person who wrote the code.
Try it
Works on Chrome, Firefox, Edge, Brave and Opera.