The update CSS media feature can be used to test how frequently (if at all) the output device is able to modify the appearance of content.


The update feature is specified as a single keyword value chosen from the list below.

Once it has been rendered, the layout can no longer be updated. Example: documents printed on paper.
The layout may change dynamically according to the usual rules of CSS, but the output device is not able to render or display changes quickly enough for them to be perceived as a smooth animation. Examples: e-book readers or severely underpowered devices.
The layout may change dynamically according to the usual rules of CSS, and the output device is not unusually constrained in speed, so regularly-updating things like CSS Animations can be used. Example: computer screens.



<p>If this text animates for you, you are using a fast-updating device.</p>


@keyframes jiggle {
  from {
    transform: translateY(0);

  to {
    transform: translateY(25px);

@media (update: fast) {
  p {
    animation: 1s jiggle linear alternate infinite;



Specification Status Comment
Media Queries Level 4
The definition of 'update' in that specification.
Candidate Recommendation Initial definition.

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support No ? No No No No
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support ? ? ? ? ? ? ?

Document Tags and Contributors

Contributors to this page: connorshea, mfluehr, y0ssar1an, Sebastianz, kscarfone, cvrebert
Last updated by: connorshea,