preserveAspectRatio
The preserveAspectRatio
attribute indicates how an element with a viewBox providing a given aspect ratio must fit into a viewport with a different aspect ratio.
Because the aspect ratio of an SVG image is defined by the viewBox
attribute, if this attribute isn't set, the preserveAspectRatio
attribute has no effect (with one exception, the <image>
element, as described below).
Example
meet (width > height)
This example shows the use of meet
when the element's width
is greater than its height
. It presents three variations, with three different alignment values: xMidYMid
, xMinYMid
, and xMaxYMid
.
html
<svg viewBox="-1 -1 202 40" xmlns="http://www.w3.org/2000/svg">
<defs>
<path
id="smiley"
d="M50,10 A40,40,1,1,1,50,90 A40,40,1,1,1,50,10 M30,40 Q36,35,42,40 M58,40 Q64,35,70,40 M30,60 Q50,75,70,60 Q50,75,30,60" />
</defs>
</svg>
html
<rect x="0" y="0" width="60" height="30">
<title>xMidYMid meet</title>
</rect>
<svg
viewBox="0 0 100 100"
width="60"
height="30"
preserveAspectRatio="xMidYMid meet"
x="0"
y="0">
<use href="#smiley" />
</svg>
html
<rect x="70" y="0" width="60" height="30">
<title>xMinYMid meet</title>
</rect>
<svg
viewBox="0 0 100 100"
width="60"
height="30"
preserveAspectRatio="xMinYMid meet"
x="70"
y="0">
<use href="#smiley" />
</svg>
html
<rect x="140" y="0" width="60" height="30">
<title>xMaxYMid meet</title>
</rect>
<svg
viewBox="0 0 100 100"
width="60"
height="30"
preserveAspectRatio="xMaxYMid meet"
x="140"
y="0">
<use href="#smiley" />
</svg>
</svg>
css
path {
fill: yellow;
stroke: black;
stroke-width: 8px;
stroke-linecap: round;
stroke-linejoin: round;
pointer-events: none;
}
rect:hover,
rect:active {
outline: 1px solid red;
}
slice (width > height)
This example shows the use of slice
when the element's width
is greater than its height
. It presents three variations, with three different alignment values: xMidYMin
, xMidYMid
, and xMidYMax
.
html
<svg viewBox="-1 -1 202 57" xmlns="http://www.w3.org/2000/svg">
<defs>
<path
id="smiley"
d="M50,10 A40,40,1,1,1,50,90 A40,40,1,1,1,50,10 M30,40 Q36,35,42,40 M58,40 Q64,35,70,40 M30,60 Q50,75,70,60 Q50,75,30,60" />
</defs>
</svg>
html
<rect x="0" y="15" width="60" height="30">
<title>xMidYMin slice</title>
</rect>
<svg
viewBox="0 0 100 100"
width="60"
height="30"
preserveAspectRatio="xMidYMin slice"
x="0"
y="15">
<use href="#smiley" />
</svg>
html
<rect x="70" y="15" width="60" height="30">
<title>xMidYMid slice</title>
</rect>
<svg
viewBox="0 0 100 100"
width="60"
height="30"
preserveAspectRatio="xMidYMid slice"
x="70"
y="15">
<use href="#smiley" />
</svg>
html
<rect x="140" y="15" width="60" height="30">
<title>xMidYMax slice</title>
</rect>
<svg
viewBox="0 0 100 100"
width="60"
height="30"
preserveAspectRatio="xMidYMax slice"
x="140"
y="15">
<use href="#smiley" />
</svg>
</svg>
css
path {
fill: yellow;
stroke: black;
stroke-width: 8px;
stroke-linecap: round;
stroke-linejoin: round;
pointer-events: none;
}
rect:hover,
rect:active {
outline: 1px solid red;
}
meet (height > width)
This example shows the use of meet
when the element's height
is greater than its width
. It presents three variations, with three different alignment values: xMidYMin
, xMidYMid
, and xMidYMax
.
html
<svg viewBox="-1 -1 202 80" xmlns="http://www.w3.org/2000/svg">
<defs>
<path
id="smiley"
d="M50,10 A40,40,1,1,1,50,90 A40,40,1,1,1,50,10 M30,40 Q36,35,42,40 M58,40 Q64,35,70,40 M30,60 Q50,75,70,60 Q50,75,30,60" />
</defs>
</svg>
html
<rect x=0" y="0" width="30" height="75">
<title>xMidYMin meet</title>
</rect>
<svg
viewBox="0 0 100 100"
width="30"
height="75"
preserveAspectRatio="xMidYMin meet"
x="0"
y="0">
<use href="#smiley" />
</svg>
html
<rect x="35" y="0" width="30" height="75">
<title>xMidYMid meet</title>
</rect>
<svg
viewBox="0 0 100 100"
width="30"
height="75"
preserveAspectRatio="xMidYMid meet"
x="35"
y="0">
<use href="#smiley" />
</svg>
html
<rect x="70" y="0" width="30" height="75">
<title>xMidYMax meet</title>
</rect>
<svg
viewBox="0 0 100 100"
width="30"
height="75"
preserveAspectRatio="xMidYMax meet"
x="70"
y="0">
<use href="#smiley" />
</svg>
</svg>
css
path {
fill: yellow;
stroke: black;
stroke-width: 8px;
stroke-linecap: round;
stroke-linejoin: round;
pointer-events: none;
}
rect:hover,
rect:active {
outline: 1px solid red;
}
slice (height > width)
This example shows the use of slice
when the element's height
is greater than its width
. It presents three variations, with three different alignment values: xMinYMid
, xMidYMid
, and xMaxYMid
.
html
<svg viewBox="-1 -1 202 80" xmlns="http://www.w3.org/2000/svg">
<defs>
<path
id="smiley"
d="M50,10 A40,40,1,1,1,50,90 A40,40,1,1,1,50,10 M30,40 Q36,35,42,40 M58,40 Q64,35,70,40 M30,60 Q50,75,70,60 Q50,75,30,60" />
</defs>
</svg>
html
<rect x="0" y="0" width="30" height="75">
<title>xMinYMid slice</title>
</rect>
<svg
viewBox="0 0 100 100"
width="30"
height="75"
preserveAspectRatio="xMinYMid slice"
x="0"
y="0">
<use href="#smiley" />
</svg>
html
<rect x="35" y="0" width="30" height="75">
<title>xMidYMid slice</title>
</rect>
<svg
viewBox="0 0 100 100"
width="30"
height="75"
preserveAspectRatio="xMidYMid slice"
x="35"
y="0">
<use href="#smiley" />
</svg>
html
<rect x="70" y="0" width="30" height="75">
<title>xMaxYMid slice</title>
</rect>
<svg
viewBox="0 0 100 100"
width="30"
height="75"
preserveAspectRatio="xMaxYMid slice"
x="70"
y="0">
<use href="#smiley" />
</svg>
</svg>
css
path {
fill: yellow;
stroke: black;
stroke-width: 8px;
stroke-linecap: round;
stroke-linejoin: round;
pointer-events: none;
}
rect:hover,
rect:active {
outline: 1px solid red;
}
none
This example shows an element with the alignment value set to none
.
html
<svg viewBox="-1 -1 192 62" xmlns="http://www.w3.org/2000/svg">
<defs>
<path
id="smiley"
d="M50,10 A40,40,1,1,1,50,90 A40,40,1,1,1,50,10 M30,40 Q36,35,42,40 M58,40 Q64,35,70,40 M30,60 Q50,75,70,60 Q50,75,30,60" />
</defs>
</svg>
html
<!-- none -->
<rect x="0" y="0" width="160" height="60">
<title>none</title>
</rect>
<svg
viewBox="0 0 100 100"
width="160"
height="60"
preserveAspectRatio="none"
x="0"
y="0">
<use href="#smiley" />
</svg>
</svg>
css
path {
fill: yellow;
stroke: black;
stroke-width: 8px;
stroke-linecap: round;
stroke-linejoin: round;
pointer-events: none;
}
rect:hover,
rect:active {
outline: 1px solid red;
}
Syntax
preserveAspectRatio="<align> [<meetOrSlice>]"
Its value is made of one or two keywords: A required alignment value and an optional "meet or slice" reference as described below:
- Alignment value
-
The alignment value indicates whether to force uniform scaling and, if so, the alignment method to use in case the aspect ratio of the
viewBox
doesn't match the aspect ratio of the viewport. The alignment value must be one of the following keywords:-
none
Do not force uniform scaling. Scale the graphic content of the given element non-uniformly if necessary such that the element's bounding box exactly matches the viewport rectangle. Note that if
<align>
isnone
, then the optional<meetOrSlice>
value is ignored. -
xMinYMin - Force uniform scaling.
Align the
<min-x>
of the element'sviewBox
with the smallest X value of the viewport. Align the<min-y>
of the element'sviewBox
with the smallest Y value of the viewport. -
xMidYMin - Force uniform scaling.
Align the midpoint X value of the element's
viewBox
with the midpoint X value of the viewport. Align the<min-y>
of the element'sviewBox
with the smallest Y value of the viewport. -
xMaxYMin - Force uniform scaling.
Align the
<min-x>+<width>
of the element'sviewBox
with the maximum X value of the viewport. Align the<min-y>
of the element'sviewBox
with the smallest Y value of the viewport. -
xMinYMid - Force uniform scaling.
Align the
<min-x>
of the element'sviewBox
with the smallest X value of the viewport. Align the midpoint Y value of the element'sviewBox
with the midpoint Y value of the viewport. -
xMidYMid (the default) - Force uniform scaling.
Align the midpoint X value of the element's
viewBox
with the midpoint X value of the viewport. Align the midpoint Y value of the element'sviewBox
with the midpoint Y value of the viewport. -
xMaxYMid - Force uniform scaling.
Align the
<min-x>+<width>
of the element'sviewBox
with the maximum X value of the viewport. Align the midpoint Y value of the element'sviewBox
with the midpoint Y value of the viewport. -
xMinYMax - Force uniform scaling.
Align the
<min-x>
of the element'sviewBox
with the smallest X value of the viewport. Align the<min-y>+<height>
of the element'sviewBox
with the maximum Y value of the viewport. -
xMidYMax - Force uniform scaling.
Align the midpoint X value of the element's
viewBox
with the midpoint X value of the viewport. Align the<min-y>+<height>
of the element'sviewBox
with the maximum Y value of the viewport. -
xMaxYMax - Force uniform scaling.
Align the
<min-x>+<width>
of the element'sviewBox
with the maximum X value of the viewport. Align the<min-y>+<height>
of the element'sviewBox
with the maximum Y value of the viewport.
-
none
Do not force uniform scaling. Scale the graphic content of the given element non-uniformly if necessary such that the element's bounding box exactly matches the viewport rectangle. Note that if
- Meet or slice reference
-
The meet or slice reference is optional and, if provided, must be one of the following keywords:
- meet (the default) - Scale the graphic such that:
- aspect ratio is preserved
- the entire
viewBox
is visible within the viewport - the
viewBox
is scaled up as much as possible, while still meeting the other criteria
viewBox
(i.e., the area into which theviewBox
will draw will be smaller than the viewport). - slice - Scale the graphic such that:
- aspect ratio is preserved
- the entire viewport is covered by the
viewBox
- the
viewBox
is scaled down as much as possible, while still meeting the other criteria
viewBox
does not match the viewport, some of theviewBox
will extend beyond the bounds of the viewport (i.e., the area into which theviewBox
will draw is larger than the viewport).
- meet (the default) - Scale the graphic such that:
Elements
feImage
For <feImage>
, preserveAspectRatio
defines how the referenced image should fit in the rectangle define by the <feImage>
element.
Value | <align> <meetOrSlice>? |
---|---|
Default value | xMidYMid meet |
Animatable | Yes |
image
For <image>
, preserveAspectRatio
defines how the referenced image should fit in the rectangle define by the <image>
element.
Value | <align> <meetOrSlice>? |
---|---|
Default value | xMidYMid meet |
Animatable | Yes |
marker
For <marker>
, preserveAspectRatio
indicates if a uniform scaling must be performed to fit the element viewport.
Value | <align> <meetOrSlice>? |
---|---|
Default value | xMidYMid meet |
Animatable | Yes |
pattern
For <pattern>
, preserveAspectRatio
indicates if a uniform scaling must be performed to fit the element viewport.
Value | <align> <meetOrSlice>? |
---|---|
Default value | xMidYMid meet |
Animatable | Yes |
svg
For <svg>
, preserveAspectRatio
indicates if a uniform scaling must be performed to fit the element viewport.
Value | <align> <meetOrSlice>? |
---|---|
Default value | xMidYMid meet |
Animatable | Yes |
symbol
For <symbol>
, preserveAspectRatio
indicates if a uniform scaling must be performed to fit the element viewport.
Value | <align> <meetOrSlice>? |
---|---|
Default value | xMidYMid meet |
Animatable | Yes |
view
For <view>
, preserveAspectRatio
indicates if a uniform scaling must be performed to fit the element viewport.
Value | <align> <meetOrSlice>? |
---|---|
Default value | xMidYMid meet |
Animatable | Yes |
Specifications
Specification |
---|
Filter Effects Module Level 1 # element-attrdef-feimage-preserveaspectratio |
Scalable Vector Graphics (SVG) 2 # PreserveAspectRatioAttribute |