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transition-timing-function

The transition-timing-function CSS property sets how intermediate values are calculated for CSS properties being affected by a transition effect.

This, in essence, lets you establish an acceleration curve so that the speed of the transition can vary over its duration.

This acceleration curve is defined using one <timing-function> for each property to be transitioned.

You may specify multiple timing functions; each one will be applied to the corresponding property as specified by the transition-property property, which acts as a transition-property list. If there are fewer timing functions specified than in the transition-property list, the user agent must calculate which value is used by repeating the list of values until there is one for each transition property. If there are more timing functions, the list is simply truncated to the right size. In both cases, the CSS declaration stays valid.

Syntax

/* Keyword values */
transition-timing-function: ease;
transition-timing-function: ease-in;
transition-timing-function: ease-out;
transition-timing-function: ease-in-out;
transition-timing-function: linear;
transition-timing-function: step-start;
transition-timing-function: step-end;

/* Function values */
transition-timing-function: steps(4, jump-end);
transition-timing-function: cubic-bezier(0.1, 0.7, 1.0, 0.1);

/* Steps Function keywords */
transition-timing-function: steps(4, jump-start);
transition-timing-function: steps(10, jump-end);
transition-timing-function: steps(20, jump-none);
transition-timing-function: steps(5, jump-both);
transition-timing-function: steps(6, start);
transition-timing-function: steps(8, end);

/* Multiple timing functions */
transition-timing-function: ease, step-start, cubic-bezier(0.1, 0.7, 1.0, 0.1);

/* Global values */
transition-timing-function: inherit;
transition-timing-function: initial;
transition-timing-function: unset;

Values

<timing-function>
Each <timing-function> represents the timing function to link to the corresponding property to transition, as defined in transition-property.

The non-step keyword values (ease, linear, ease-in-out, etc.) each represent cubic Bézier curve with fixed four point values, with the cubic-bezier() function value allowing for a non-predefined value. The step timing functions divides the input time into a specified number of intervals that are equal in length. It is defined by a number of steps and a step position.

ease
Equal to cubic-bezier(0.25, 0.1, 0.25, 1.0), the default value, increases in velocity towards the middle of the transition, slowing back down at the end.
linear
Equal to cubic-bezier(0.0, 0.0, 1.0, 1.0), transitions at an even speed.
ease-in
Equal to cubic-bezier(0.42, 0, 1.0, 1.0), starts off slowly, with the transition speed increasing until complete.
ease-out
Equal to cubic-bezier(0, 0, 0.58, 1.0), starts transitioning quickly, slowing down the transition continues. •
ease-in-out
Equal to cubic-bezier(0.42, 0, 0.58, 1.0), starts transitioning slowly, speeds up, and then slows down again.
cubic-bezier(p1, p2, p3, p4)
An author defined cubic-Bezier curve, where the p1 and p3 values must be in the range of 0 to 1.
steps( n, <jumpterm>)
Displays the transition along n stops along the transition, displaying each stop for equal lengths of time. For example, if n is 5, there are 5 steps. Whether the transition holds temporarily at 0%, 20%, 40%, 60% and 80%, on the 20%, 40%, 60%, 80% and 100%, or makes 5 stops between the 0% and 100% along the transition, or makes 5 stops including the 0% and 100% marks (on the 0%, 25%, 50%, 75%, and 100%) depends on which of the following jump terms is used:
jump-start
Denotes a left-continuous function, so that the first jump happens when the transition begins;
jump-end
Denotes a right-continuous function, so that the last jump happens when the animation ends;
jump-none
There is no jump on either end. Instead, holding at both the 0% mark and the 100% mark, each for 1/n of the duration
jump-both
Includes pauses at both the 0% and 100% marks, effectively adding a step during the transition time.
start
Same as jump-start.
end
Same as jump-end.
step-start
Equal to steps(1, jump-start)
step-end
Equal to steps(1, jump-end)

Accessibility concerns

Some animations can be helpful such as to guide users to understand what actions are expected, to show relationships within the user interface, and to inform users as to what actions have occurred. Animations can help reduce cognitive load, prevent change blindness, and establish better recall in spatial relationships. However, some animations can be problematic for people with cognitive concerns such as Attention Deficit Hyperactivity Disorder (ADHD) and certain kinds of motion can be a trigger for Vestibular disorders, epilepsy, and migraine and Scotopic sensitivity.

Consider providing a mechanism for pausing or disabling animation, as well as using the Reduced Motion Media Query to create a complimentary experience for users who have expressed a preference for no animated experiences.

Formal definition

Initial value ease
Applies to all elements, ::before and ::after pseudo-elements
Inherited no
Computed value as specified
Animation type discrete

Formal syntax

<timing-function>#

where
<timing-function> = linear | <cubic-bezier-timing-function> | <step-timing-function>

where
<cubic-bezier-timing-function> = ease | ease-in | ease-out | ease-in-out | cubic-bezier(<number <a href="/en-US/docs/CSS/Value_definition_syntax#Brackets" title="Brackets: enclose several entities, combinators, and multipliers to transform them as a single component">[0,1]>, <number>, <number <a href="/en-US/docs/CSS/Value_definition_syntax#Brackets" title="Brackets: enclose several entities, combinators, and multipliers to transform them as a single component">[0,1]>, <number>)
<step-timing-function> = step-start | step-end | steps(<integer>[, <step-position>]?)

where
<step-position> = jump-start | jump-end | jump-none | jump-both | start | end

Examples

Cubic-Bezier examples

.ease {
   transition-timing-function: ease;
}
.easein {
   transition-timing-function: ease-in;
}
.easeout {
   transition-timing-function: ease-out;
}
.easeinout {
   transition-timing-function: ease-in-out;
}
.linear {
   transition-timing-function: linear;
}
.cb {
   transition-timing-function: cubic-bezier(0.2,-2,0.8,2);
}

Step examples

.jump-start {
   transition-timing-function: steps(5, jump-start);
}
.jump-end {
   transition-timing-function: steps(5, jump-end);
}
.jump-none {
   transition-timing-function: steps(5, jump-none);
}
.jump-both {
   transition-timing-function: steps(5, jump-both);
}
.step-start {
   transition-timing-function: step-start;
}
.step-end {
   transition-timing-function: step-end;
}

Specifications

Specification Status Comment
CSS Transitions
The definition of 'transition-timing-function' in that specification.
Working Draft Initial definition

Browser compatibilityUpdate compatibility data on GitHub

Desktop
Chrome Edge Firefox Internet Explorer Opera Safari
transition-timing-function 26
26
1
Prefixed
Prefixed Implemented with the vendor prefix: -webkit-
12
12
12
Prefixed
Prefixed Implemented with the vendor prefix: -webkit-
16
16
4
Prefixed
Prefixed Implemented with the vendor prefix: -moz-
49
Prefixed
Prefixed Implemented with the vendor prefix: -webkit-
44
Prefixed Disabled
Prefixed Implemented with the vendor prefix: -webkit-
Disabled From version 44: this feature is behind the layout.css.prefixes.webkit preference (needs to be set to true). To change preferences in Firefox, visit about:config.
10
10
10
Prefixed
Prefixed Implemented with the vendor prefix: -ms-
12.1
12.1
15
Prefixed
Prefixed Implemented with the vendor prefix: -webkit-
11.6 — 15
Prefixed
Prefixed Implemented with the vendor prefix: -o-
9
9
3.1
Prefixed
Prefixed Implemented with the vendor prefix: -webkit-
jump- keywords for steps() 77 79 65 No 64 14
Mobile
Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet
transition-timing-function ≤37
≤37
≤37
Prefixed
Prefixed Implemented with the vendor prefix: -webkit-
26
26
18
Prefixed
Prefixed Implemented with the vendor prefix: -webkit-
16
16
4
Prefixed
Prefixed Implemented with the vendor prefix: -moz-
49
Prefixed
Prefixed Implemented with the vendor prefix: -webkit-
44
Prefixed Disabled
Prefixed Implemented with the vendor prefix: -webkit-
Disabled From version 44: this feature is behind the layout.css.prefixes.webkit preference (needs to be set to true). To change preferences in Firefox, visit about:config.
12.1
12.1
14
Prefixed
Prefixed Implemented with the vendor prefix: -webkit-
12 — 14
Prefixed
Prefixed Implemented with the vendor prefix: -o-
9
9
2
Prefixed
Prefixed Implemented with the vendor prefix: -webkit-
1.5
1.5
1.0
Prefixed
Prefixed Implemented with the vendor prefix: -webkit-
jump- keywords for steps() 77 77 65 55 14 12.0

See also

© 2005–2020 Mozilla and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/CSS/transition-timing-function