Your scores stay on your device. ReflexLab has no accounts, no sign-ups, and no server that receives your results. Two things do involve a third party: Google Analytics measures traffic, and our host logs the requests it serves. Both are described below.
What ReflexLab Stores
Every test writes to your browser's localStorage under keys beginning with reflexlab:. For each test on the site, that covers:
- Your personal best, and the settings you set it under
- Your recent run history, with a timestamp on each run
- Which rank tiers or milestones you have reached
- Your settings for that test, such as duration, delay, input method, and sound
None of it is transmitted. It stays in the browser profile that wrote it, which also means your scores will not follow you to another browser or another device. If you used ReflexLab before its rebuild, you may still hold keys beginning reactionlab_ or cpslab_ from the earlier version of the site. Those were imported once so your old personal bests survived, and the Reset button erases them along with everything else.
No Accounts or Sign-Ups
ReflexLab never asks you to create an account, give an email address, or sign in. Open a test and take it. We hold no personal information about you because we never collect any.
Deleting Your Data
Each test has its own Reset button in the toolbar above the test area. It clears that test's personal best, run history, trend graph, and achieved ranks, and it leaves your settings in place so you do not have to rebuild them.
Reset acts on the test you are looking at. Clearing your CPS data leaves your reaction time scores untouched. To erase every test at once, clear this site's data through your browser settings.
Cookies
ReflexLab sets no cookies of its own. Your scores and settings live in localStorage, which is separate from cookies and never travels with a network request. Google Analytics does set cookies, described next.
Analytics
ReflexLab uses Google Analytics to count page views and see which tests people use. It collects the standard set: the pages you visit, your approximate location down to country or region, your device type, and your browser. It never receives your scores, which stay in localStorage and are never read by the analytics script.
The script loads from googletagmanager.com and sets cookies that tell a repeat visit from a new one. These cookies carry no personally identifiable information. To opt out, install Google's browser add-on, block the domain with an extension, or turn off cookies for this site.
For more information, see Google's Privacy Policy.
Hosting
Vercel hosts ReflexLab. Like any web host, its servers log the requests they serve, and those logs include your IP address, the page you asked for, and your user agent. We do not use them to build a profile of you or link them to anything else.
See Vercel's Privacy Policy for how they handle that data.
What We Do Not Do
We do not ask for your name or email address, sell or share your data, or track you across other websites. Nothing you do inside a test reaches us.
Changes to This Policy
When what the site does changes, this page changes with it, and the date at the top of the page moves to match. Anything material gets written here rather than announced elsewhere.