Operable Guideline 2.5 Input Modalities

2.5.4 Motion Actuation

Shake and tilt controls need a normal alternative and an off switch

Level A Needs a person to check

What it asks for, in plain English

If something on your page is triggered by moving the device or the person, such as shake to undo, tilt to scroll, turn the phone to see a panorama, or wave at the camera to go to the next slide, then the same thing must also be possible with ordinary controls like buttons, and the person must be able to switch the motion trigger off.

The reason for the off switch is that some people move involuntarily, and a phone on a wheelchair tray gets shaken all day. Motion input that cannot be disabled makes the page fire actions at random.

Two exceptions: motion that comes through an accessibility-supported interface, such as a head tracker the person has chosen, and motion that is essential, such as a pedometer counting steps.

This is an independent explanation. The binding wording is the W3C Recommendation, and the W3C's own Understanding 2.5.4 page has the full intent, techniques and definitions.

Who it affects

Someone with a tremor or spasticity shakes the phone unintentionally and keeps undoing their own typing.

A person with a tablet fixed to a wheelchair cannot tilt or shake the device at all, so a tilt-only feature is closed to them.

Anyone using a phone on a train triggers motion features from the carriage movement.

How to check it

  1. On a phone, shake, tilt and rotate the device on each key page, and wave in front of the camera if it is in use. Note anything that responds.
  2. For each motion feature, find a button or control that does the same thing.
  3. Look for a setting that turns the motion trigger off, and check the feature still works from the button when it is off.
  4. Check that the operating system's reduce motion setting is respected where the page can read it.

What Websight checks for 2.5.4

Websight has no automated check for this criterion. It lists it in the manual checklist that comes with every report, so it is not forgotten.

Only a person can check this. A scanner cannot move a device or know what the page listens for.

Practical tips

  • Treat motion as a shortcut, never as the only way.
  • Put the on-off switch for motion features in an obvious settings area and default it to off if the feature is a novelty.
  • Most sites have no motion features at all, in which case this passes with nothing to do.

Scan your page and see where 2.5.4 stands

Websight gives a score out of 100, explains each automated finding in plain English, and lists the checks a person still needs to do.

Add Websight to Chrome

Free scans, no account, nothing leaves your computer. Automated tools find only part of the problems; the extension says so on every report.