Some of my studies involve online web-based experiments. Here are some examples. Note: these tasks have been tested with Google Chrome. They may not operate correctly with other browsers.
1. Intention offloading task
This is a task in which participants hold briefly delayed intentions, in some conditions with an option to set an external reminder if they wish. You can set a reminder by dragging a target circle towards its instructed location at the beginning of the trial, so that it's location reminds you where it should be dragged when you reach its position in the sequence.

For further details see:

Gilbert, S.J. (2015). Strategic offloading of delayed intentions into the external environment. Quarterly Journal of Experimental Psychology, 68, 971-992.   [pdf]
Link (opens in new window)
2. Perceptual metacognition tasks
These tasks require a perceptual discrimination on each trial, which gets progressively more difficult to stabilise performance at about 70% correct. After the initial practice trials, participants must provide a condfidence rating on each trial, allowing investigation of the relationship between objective accuracy and subjective confidence.

For further details see:

Gilbert, S.J. (2015). Strategic use of reminders: Influence of both domain-general and task-specific metacognitive confidence, independent of objective memory ability.Consciousness and Cognition, 33, 245-260.   [pdf]
Link (opens in new window)
© Sam Gilbert 2016