No Visual Motion
Group: animation-and-movement • Guideline: avoid-physical-harm
Summary in Plain English
Visual motion and pseudo-motion - things like parallax scrolling and moving backgrounds - must not run longer than five seconds, unless the motion is essential.
Why It Matters
Sustained motion can cause nausea, dizziness and migraine in people with vestibular disorders, and it pulls attention away from the content for people with attention-related disabilities.
Scope: When This Applies
The draft's own conditions, quoted from guidelines/groups/animation-and-movement/avoid-physical-harm/no-visual-motion.md.
Except when
- The motion or pseudo-motion is essential.
Test Procedure from the W3C Draft
Quoted from the provision's informative document, informative/guidelines/animation-and-movement/avoid-physical-harm/no-visual-motion.md. It is the group's own procedure, not an editorial testing guide.
Procedure
For each page/view:
- Check if content includes visual motion or pseudo-motion.
- For each instance, check that the visual motion or pseudo-motion is essential.
Expected results
- #1 is false, or
- #2 is true.
Methods Suggested Upstream
Implementation methods listed in the informative document.
- Consider if motion or pseudo-motion is essential, and if it is not, refrain from including it.
W3C Working Group Status
The draft records no open editors' notes on this provision.
W3C Threads on This Provision
5 GitHub threads carrying 35 comments, fetched from w3c/wcag3 by the tracker. Titles, numbers and states are the threads' own.
What the Argument Is About
Whether honouring prefers-reduced-motion can satisfy the requirement, and whether motion harm belongs at the base level rather than as an optional extra.
Positions taken in the thread
The WCAG 2 equivalent sits at AAA, which in practice means it is ignored. If a user has set prefers-reduced-motion, respecting it should be required, not aspirational. guyhickling argues a mechanism to stop animation is no help when the harm lands before the user reaches the control — particularly for keyboard users.
prefers-reduced-motion is a single binary flag, but users are usually affected by specific kinds of motion, and the setting is sometimes enabled accidentally. Treating it as "turn off all animation" is too draconian for a normative requirement and risks developers writing WCAG off entirely.
Defining size and duration across devices and zoom levels is where this previously broke down, and duration is undefined when the motion is triggered by user action such as scrolling. Moving it to a base level requires evidence of impact at a given size and speed, and a consensus process means persuading those who objected last time.
A study demonstrating harm from motion would harm its participants. Also argues the need is broader than vestibular illness: hyper-vigilance and attention impairments mean even small, sub-second animation costs time and mental energy to recover from. alastc replied that such a study need not force anyone to view animations — participants could log the animations they encounter and the symptoms triggered — and that whether there is an impact is believed and understood; the question is what specifically triggers symptoms.
Agreed
- That motion causes real harm to some users is not in dispute: alastc, who brought the WCAG 2.1 criterion, says the impact is believed and understood, and patrickhlauke's objection is to the breadth of the remedy, not the need. The disagreement is over what specifically triggers symptoms and where to draw the line.
Still open
- Whether a user preference can be relied on to satisfy the requirement at all. In #629 alastc asked this of the flashing note and said it applies equally to reduced motion; julierawe called it dangerous for flashing, asking what happens when someone looks at another person's device, and alastc doubts such a preference is accessibility supported today.
- How to define a size and duration threshold that is testable without a screen ruler, which patrickhlauke raised as a reductio and mgifford answered by pointing out 4.5:1 looked equally arbitrary in 2008.
- Whether "pseudo-motion" should get examples in its definition and its own provision. julierawe filed #739 for the COGA Task Force proposing parallax scrolling, sharp colour changes, dynamically updating content and others, and asking that No pseudo-motion stand alone so it cannot be read as allowed under 5 seconds; rachaelbradley suggested the decoy font as a possible example, mraccess77 said it gives him a headache, and julierawe added gamma-oscillation and sliced images. In October 2026, Charles Hall reported that pseudo-motion is now an active draft provision (currently supplemental, with research indicating harm comparable to actual motion) and includes a mechanism to prevent, turn off, or hide pseudo-motion.
- Whether small animations are triggers. alastc said the WCAG 2.1 work found small animations such as icons changing on hover were not, so a minimum size seemed necessary; mraccess77 replied that jiggling icons do impact some users and supplied a live example.
- Whether the Windows reduced-motion switch is too coarse. mraccess77 reports it blocks animations they want along with those they do not and wants finer control, whereas CharlesBelov and guyhickling treat the on/off switch as a clear statement that animation should stop.
- Whether the time limits for auto-playing audio (3 seconds) and moving or auto-updating content (5 seconds) should be unified. Wildebrew asked in #181 and recommended folding the auto-playing audio requirement into 2.2.2's equivalent; when alastc floated increasing 1.4.2's time instead, Wildebrew backed 5 seconds and asked that WCAG 3 group all page-level animation and sound together. alastc and bruce-usab were reluctant to change it within 2.x, and bruce-usab noted three seconds for both would also be logical.
- julierawe's separate objection (#733) that naming the guideline "Avoid Physical Harm" excludes the cognitive harm — lost focus, fatigue, re-orientation cost — that motion also causes.
- #27 Not hurting users should be standard, not aaa open 1 comment · updated 2026-04-16
- #181 Why is length of audio (1.4.2) and auto updating content (2.2.2) different? open 3 comments · updated 2026-05-02
- #183 Public Comment on 2.3.3 Animation from Interactions and prefers-reduced-motion open 23 comments · updated 2026-05-02
- #629 Can user-preferences be relied on for "No flashing"? open 4 comments · updated 2026-06-15
- #739 Pseudo-motion: Expand to include examples, and consider making this its own provision. open 4 comments · updated 2026-10-06
WCAG 2.2 Criteria That Map Here
From this site's reviewed WCAG 2.2 → WCAG 3 map. The map is an interpretation, not a W3C mapping: W3C has not published one yet.
Related WCAG 2.2 criteria
On a neighbouring subject, but this provision doesn't replace them.
W3C Raw Source Text
Verbatim from guidelines/groups/animation-and-movement/avoid-physical-harm/no-visual-motion.md · informative document: informative/guidelines/animation-and-movement/avoid-physical-harm/no-visual-motion.md
Content does not include pseudo-motion or visual motion lasting longer than 5 seconds. :::except-when - The motion or pseudo-motion is essential. :::