Motion actuation

Silktide detects pages that respond to a device being moved, shaken, or tilted. Anything a page does in response to motion should also be possible through ordinary controls, and it should be possible to turn the motion feature off.

Why this matters

Features like "shake to undo" or tilt-to-scroll assume a visitor can move their device deliberately and precisely. Many cannot: a person with tremors or Parkinson's moves constantly and triggers motion features by accident, a wheelchair user's device shakes with every bump, and a device mounted to a desk or wheelchair cannot be shaken at all. Without an ordinary button or setting that does the same thing, these visitors either trigger the feature unintentionally or cannot use it at all.

This is success criterion 2.5.4 (Motion Actuation), a requirement - part of the most basic conformance level.

How to fix it

For each motion feature Silktide finds, confirm two things:

There is an alternative - the same action can be performed with normal controls, such as a button, link, or form field.
It can be disabled - visitors can switch the motion response off, so accidental movement does not trigger it.

If either is missing, add it. If both are already in place, or the motion response is essential to the feature (such as a pedometer reading), you can the finding.

How Silktide tests this

Load each page in a real browser and record the event listeners it registers.
Report every listener for device motion or device orientation events - the browser events pages use to react to movement and tilting.
Show the listener's code in the finding so you can identify which feature it belongs to.
Because Silktide cannot tell whether your page also offers an ordinary control for the same action, findings are flagged for your confirmation rather than counted as confirmed failures.

Troubleshooting

The listener comes from a third-party script

Analytics, advertising, and framework scripts sometimes listen for motion events you never use as a feature. If the listener does not trigger any functionality, it cannot violate this criterion; approve the finding.

The motion feature is essential

WCAG allows motion input when the motion itself is the point - for example, a step counter or a spirit-level tool. Approve the finding if this applies.