`font-weight` CSS property

The font-weight CSS property sets the weight (or boldness) of the font. The weights available depend on the font-family that is currently set.

Try it

font-weight: normal;

font-weight: bold;

font-weight: lighter;

font-weight: bolder;

font-weight: 100;

font-weight: 900;

<section id="default-example">
  <p id="example-element">
    London. Michaelmas term lately over, and the Lord Chancellor sitting in
    Lincoln's Inn Hall. Implacable November weather. As much mud in the streets
    as if the waters had but newly retired from the face of the earth, and it
    would not be wonderful to meet a Megalosaurus, forty feet long or so,
    waddling like an elephantine lizard up Holborn Hill.
  </p>
</section>

section {
  font-size: 1.2em;
}

Syntax

css

/* <font-weight-absolute> keyword values */
font-weight: normal;
font-weight: bold;

/* <font-weight-absolute> numeric values [1,1000] */
font-weight: 100;
font-weight: 200;
font-weight: 300;
font-weight: 400; /* normal */
font-weight: 500;
font-weight: 600;
font-weight: 700; /* bold */
font-weight: 800;
font-weight: 900;

/* Keyword values relative to the parent */
font-weight: lighter;
font-weight: bolder;

/* Global values */
font-weight: inherit;
font-weight: initial;
font-weight: revert;
font-weight: revert-layer;
font-weight: unset;

Values

This property is specified as a single value from the following list:

normal: Normal font weight. Same as 400.
bold: Bold font weight. Same as 700.
<number>: A <number> value between 1 and 1000, both values included. Higher numbers represent weights that are bolder than (or as bold as) lower numbers. This allows fine-grain control for variable fonts. For non-variable fonts, if the exact specified weight is unavailable, a fallback weight algorithm is used — numeric values that are divisible by 100 correspond to common weight names, as described in the Common weight name mapping section below.
lighter: One relative font weight lighter than the parent element. Note that only four font weights are considered for relative weight calculation; see the Meaning of relative weights section below.
bolder: One relative font weight heavier than the parent element. Note that only four font weights are considered for relative weight calculation; see the Meaning of relative weights section below.

Fallback weights

If the exact weight given is unavailable, then the following rule is used to determine the weight actually rendered:

If the target weight given is between 400 and 500 inclusive:
- Look for available weights between the target and 500, in ascending order.
- If no match is found, look for available weights less than the target, in descending order.
- If no match is found, look for available weights greater than 500, in ascending order.
If a weight less than 400 is given, look for available weights less than the target, in descending order. If no match is found, look for available weights greater than the target, in ascending order.
If a weight greater than 500 is given, look for available weights greater than the target, in ascending order. If no match is found, look for available weights less than the target, in descending order.

Note: The fallback weight algorithm is only used for rendering. The computed value of the property is still the specified value.

Meaning of relative weights

When lighter or bolder is specified, the below chart shows how the absolute font weight of the element is determined.

Note that when using relative weights, only four font weights are considered — thin (100), normal (400), bold (700), and heavy (900). If a font family has more weights available, they are ignored for the purposes of relative weight calculation.

Inherited value	`bolder`	`lighter`
100	400	100
200	400	100
300	400	100
400	700	100
500	700	100
600	900	400
700	900	400
800	900	700
900	900	700

Common weight name mapping

The numerical values 100 to 900 roughly correspond to the following common weight names (see the OpenType specification):

Value	Common weight name
100	Thin (Hairline)
200	Extra Light (Ultra Light)
300	Light
400	Normal (Regular)
500	Medium
600	Semi Bold (Demi Bold)
700	Bold
800	Extra Bold (Ultra Bold)
900	Black (Heavy)
950	Extra Black (Ultra Black)

Variable fonts

While many fonts have a particular weight corresponding to one of the numbers in Common weight name mapping, most variable fonts support a range of weights providing much finer granularity, giving designers and developers more control over the chosen weight.

For TrueType or OpenType variable fonts, the "wght" variation is used to implement varying widths.

This demo loads with font-weight: 500; set. Change the value of the font-weight property in the .sample selector to see the weight of the text change (e.g., 200, 700). Click "Play" in the code blocks below to edit the example in the MDN Playground:

html

<p class="sample">
  ...it would not be wonderful to meet a Megalosaurus, forty feet long or so,
  waddling like an elephantine lizard up Holborn Hill.
</p>

css

@font-face {
  src: url("https://mdn.github.io/shared-assets/fonts/variable-fonts/MutatorSans.ttf");
  font-family: "MutatorSans";
  font-style: normal;
  font-weight: 1 1000;
}

.sample {
  text-transform: uppercase;
  font-weight: 500;
  font-size: 1.5rem;
  font-family: "MutatorSans", sans-serif;
}

Accessibility

People experiencing low vision conditions may have difficulty reading text set with a font-weight value of 100 (Thin/Hairline) or 200 (Extra Light), especially if the font has a low contrast color ratio.

Formal definition

Initial value	`normal`
Applies to	all elements and text. It also applies to `::first-letter` and `::first-line`.
Inherited	yes
Computed value	the keyword or the numerical value as specified, with `bolder` and `lighter` transformed to the real value
Animation type	by computed value type

Formal syntax

font-weight = 
  <font-weight-absolute>  |
  bolder                  |
  lighter                 

<font-weight-absolute> = 
  normal             |
  bold               |
  <number [1,1000]>

Examples

undefined

Setting font weights

HTML