The <number> CSS data type represents a number, being either an integer or a number with a fractional component.


The syntax of <number> extends the syntax of <integer>. A fractional value is represented by a . followed by one or more decimal digits, and may be appended to an integer. There is no unit associated with numbers.


When animated, values of the <number> CSS data type are interpolated as real, floating-point numbers. The speed of the interpolation is determined by the timing function associated with the animation.


Valid numbers

12          A raw <integer> is also a <number>.
4.01        Positive fraction
-456.8      Negative fraction
0.0         Zero
+0.0        Zero, with a leading +
-0.0        Zero, with a leading -
.60         Fractional number without a leading zero
10e3        Scientific notation
-3.4e-2     Complicated scientific notation

Invalid numbers

12.         Decimal points must be followed by at least one digit.
+-12.2      Only one leading +/- is allowed.
12.1.1      Only one decimal point is allowed.


Specification Status Comment
CSS Values and Units Module Level 3
The definition of '<number>' in that specification.
Candidate Recommendation No significant change.
CSS Level 2 (Revision 1)
The definition of '<number>' in that specification.
Recommendation Explicit definition.
CSS Level 1
The definition of '<number>' in that specification.
Recommendation Implicit definition.

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support1 Yes15 Yes1
Scientific notation43 Yes2911 ? ?
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support Yes Yes Yes Yes Yes Yes Yes
Scientific notation Yes Yes Yes Yes Yes Yes Yes

See also

Document Tags and Contributors

Last updated by: fscholz,