Privacy

Exact test runs stay in your browser. Product analytics, when enabled, uses only fixed aggregate buckets and no account identifier.

Local device data

The latest 20 completed runs are stored under a versioned browser localStorage key. Each record contains a local ID, completion time, average, median, best, consistency, false-start count and input class. The separate analytics opt-out preference is also stored locally. Clearing site data removes both.

Challenge links

A challenge link contains the target average, best score and an optional public display name of up to 24 characters. Anyone with the link can read that data. Do not enter private or sensitive information as a display name.

Aggregate analytics

Cloudflare Web Analytics may provide aggregate visits and performance measurements. A same-origin product endpoint may record fixed events and broad score, false-start, input, share and challenge-outcome buckets. It does not accept exact milliseconds, names, query strings, raw referrers, answers, free text, Cookie values, user IDs, session IDs or device IDs.

Cloudflare necessarily processes request information to deliver and protect the site. Reaction Test Lab does not add IP addresses or User-Agent values to the product-event dataset. Product events are designed to be aggregate and cannot be used to retrieve or delete an individual's exact run.

Your controls

The site respects Global Privacy Control and browser Do Not Track for product events. You can also disable product analytics on this device below. Local test history remains available unless you clear it separately.

Contact

For privacy questions, contact YJ at [email protected].