The site, on Steam's own page.

The panel goes under the purchase area, in the same amber this site counts hours in, and it is the only thing the extension adds to that page. Nothing is moved, nothing is covered, and nothing the store already did stops working.

The figures are the public ones: how many people are in the game at this moment, the review split with the newest reviews beside the whole history, the release date, and how long ago the studio last posted - which says the game is being talked about, not that it was updated. The trailer is Steam's own file, and nothing crosses the network until somebody presses the button.

Under all of it sits one section that is about you and starts switched off. Turned on, it adds your hours in that game and how much of its achievement set you have, read from the profile Steam already publishes to anybody.

An extension can be given every page you open, which is why what this one may touch is short enough to print here in full.

• Steam, and nothing else. It runs on Steam's own domains and nowhere else. Every other tab is out of its reach.
• Two addresses, both ours. The appid already in the page URL and the catalogue language go to steamprofiler.org/api/companion, which answers with public store facts. The second, /api/companion/profile, is called only if you switch the section below on. Every reply is checked before a single value reaches the page.
• Your profile, and only if you say so. "Use my profile" starts off. Turned on, the extension takes the public SteamID that Steam itself prints in the page header, or the one you typed in the settings, and sends it with the appid to that second address. What comes back is your hours and your achievements in that one game. No cookie is read to find it, and game details set to private stay private here exactly as they do on the site.
• Your own switches. The panel, the metrics, the trailer, the language, the profile consent and any SteamID you typed live in the browser's extension storage, which your browser may sync between your own devices. The switches themselves are never sent anywhere.
• No sign-in, and no credential. No cookies, no session, no login, no password, no API key, no browsing history, no analytics and no ads. The most this extension can know about you is a public SteamID you handed it on purpose, which is the same number anybody can read off your profile page.

It is not in the Chrome Web Store or on addons.mozilla.org yet. When it is, the button will be on this page. Until then it installs from its own repository, out of the same zip the stores will be given.

• Chrome, Edge, Brave. Unpack the release zip, open chrome://extensions, turn developer mode on, and choose "Load unpacked".
• Firefox. Open about:debugging, choose "This Firefox", then "Load Temporary Add-on", and pick the manifest.json inside the unpacked folder.

Manifest V3, one source tree for both browsers, no framework, no bundler and no remotely hosted code. What is in the zip is what runs.

• The source of the extension ↗
• What it sends, in its own words ↗
• The privacy policy of this site
• Tell me the panel is broken

The extension is ours; the store page is not. It adds a panel to a page Valve serves, it is not affiliated with Valve, and it goes quiet the day either Steam or this site stops answering.