Beat the score that came before
Rival Yourself
Each challenge can show the result that existed when you opened the page, giving you a stable ghost target for that session instead of moving the goalpost after every run.
Current ghost targets
Your last-run rivals.
Targets are separated by challenge difficulty and are never compared with population benchmarks.
Why use a ghost target?
A personal best can become difficult to beat every session. A last-run target gives you a nearer opponent: your own previous performance. When you open a challenge, the target is captured for that page session, so finishing a new run does not immediately change the number you were trying to beat.
Private by design
Ghost targets use the same local browser history as the rest of the Performance Lab. No score is uploaded and there is no public ranking.