The short version
This site has no server of its own and no database. Sound, video, photos, key presses and test results are processed inside your browser and are never sent anywhere.
Camera and microphone
A test only asks for your camera or microphone when you start it, and your browser shows its own permission prompt. The stream is used to draw a level meter or a preview and is stopped when you leave the page. Recordings and snapshots stay in your device memory until you close the tab, unless you save them yourself.
What is stored on your device
We use your browser local storage for two small things: the language you picked and whether you prefer the light or dark theme. Nothing else is stored, and clearing your browser data removes them.
Shared links
Reaction duel links and device check reports carry their data inside the part of the address after the “#” symbol. Browsers never send that part to a server, so the data travels only to the person you send the link to.
Analytics
We use Cloudflare Web Analytics to count page views. It does not use cookies, does not fingerprint visitors and does not track people across sites.
Advertising
This site shows ads from Google AdSense. Third-party vendors, including Google, use cookies to serve ads based on your prior visits to this website or other websites.
Google’s use of advertising cookies enables it and its partners to serve ads to you based on your visits to this site and other sites on the internet. Read how Google uses information from sites that use its services.
You can opt out of personalised advertising in Google Ads Settings. You can also opt out of some third-party vendors’ use of cookies for personalised advertising at www.aboutads.info, and in Europe at www.youronlinechoices.eu.
If you are in the European Economic Area, the United Kingdom or Switzerland, Google shows its own consent message before any such cookie is set, and you can change your answer at any time through that message.
Your browser settings also let you block or delete cookies entirely.
Hosting
The site is hosted by Cloudflare. Like any web host, Cloudflare processes technical request data such as your IP address to deliver the page and protect the service.
Children
This site is not aimed at children under 13 and does not knowingly collect information from them.
Changes
If this policy changes, the date above changes with it.