files/en-us/web/css/reference/properties/font-weight/index.md
The font-weight CSS property sets the weight (or boldness) of the font. The weights available depend on the {{cssxref("font-family")}} that is currently set.
{{InteractiveExample("CSS Demo: font-weight")}}
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;
}
/* <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;
The font-weight property is specified using either a <font-weight-absolute> value or a relative weight value, as listed below.
normal
400.bold
700.<number>
lighter
bolder
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:
500, in ascending order.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.
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.
<table class="standard-table"> <thead> <tr> <th>Inherited value</th> <th><code>bolder</code></th> <th><code>lighter</code></th> </tr> </thead> <tbody> <tr> <th>100</th> <td>400</td> <td>100</td> </tr> <tr> <th>200</th> <td>400</td> <td>100</td> </tr> <tr> <th>300</th> <td>400</td> <td>100</td> </tr> <tr> <th>400</th> <td>700</td> <td>100</td> </tr> <tr> <th>500</th> <td>700</td> <td>100</td> </tr> <tr> <th>600</th> <td>900</td> <td>400</td> </tr> <tr> <th>700</th> <td>900</td> <td>400</td> </tr> <tr> <th>800</th> <td>900</td> <td>700</td> </tr> <tr> <th>900</th> <td>900</td> <td>700</td> </tr> </tbody> </table>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) |
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:
<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>
@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;
}
{{EmbedLiveSample("font-weight-example", "", "200px")}}
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.
{{cssinfo}}
{{csssyntax}}
<p>
Alice was beginning to get very tired of sitting by her sister on the bank,
and of having nothing to do: once or twice she had peeped into the book her
sister was reading, but it had no pictures or conversations in it, "and what
is the use of a book," thought Alice "without pictures or conversations?"
</p>
<div>
I'm heavy
<span>I'm lighter</span>
</div>
/* Set paragraph text to be bold. */
p {
font-weight: bold;
}
/* Set div text to two steps heavier than
normal but less than a standard bold. */
div {
font-weight: 600;
}
/* Set span text to be one step lighter
than its parent. */
span {
font-weight: lighter;
}
{{EmbedLiveSample("Setting_font_weights","400","300")}}
{{Specifications}}
{{Compat}}