What is FastX?
FastX is a collection of free browser-based reflex, aim, memory, and speed tests. Each one runs in your browser — no install, no signup, no data collected. Results are stored locally so you can chase your personal best across sessions, and each test ranks you on a percentile curve with an honest letter grade.
New here? Start with this
- Just curious about your reflexes? Try the reaction time test first — ten seconds, tells you how you compare to the average human.
- Want to train for a specific game? Head to the Lab — pick a skill goal (Reaction / Aim / Speed / Memory) and get a curated routine.
- Want the theory? Read Why Speed Matters in Gaming — the four speed skills, what each one does, and how to train it.
How are scores calculated?
Each test produces a raw score (ms, CPS, WPM, etc.) which gets mapped to a skill percentile based on real public data. The percentile maps to a letter grade from F to S+. Your composite FastX Score is the average of your skill percentiles across every test you’ve completed.