font-synthesis-style

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨March 2023⁩.

The font-synthesis-style CSS property lets you specify whether or not the browser may synthesize the oblique typeface when it is missing in a font family.

It is often convenient to use the shorthand property font-synthesis to control all typeface synthesis values.

Syntax

css

/* Keyword values */ font-synthesis-style: auto; font-synthesis-style: none; font-synthesis-style: oblique-only; /* Global values */ font-synthesis-style: inherit; font-synthesis-style: initial; font-synthesis-style: revert; font-synthesis-style: revert-layer; font-synthesis-style: unset;

Values

auto: Indicates that the missing oblique typeface may be synthesized by the browser if needed.
none: Indicates that the synthesis of the missing oblique typeface by the browser is not allowed.
oblique-only: Same as auto, but no font synthesis occurs if font-style: italic is set.

Formal definition

Initial value	`auto`
Applies to	all elements and text. It also applies to `::first-letter` and `::first-line`.
Inherited	yes
Computed value	as specified
Animation type	discrete

Formal syntax

font-synthesis-style = 
 auto |
 none |
 oblique-only

Examples

Disabling synthesis of oblique typeface

This example shows turning off synthesis of the oblique typeface by the browser in the Montserrat font.

HTML

html

<p class="english"> This is the default <em>oblique typeface</em> and <strong>bold typeface</strong>. </p> <p class="english no-syn"> The <em>oblique typeface</em> is turned off here but not the <strong>bold typeface</strong>. </p>

CSS

css

@import "https://fonts.googleapis.com/css2?family=Montserrat&display=swap"; .english { font-family: "Montserrat", sans-serif; } .no-syn { font-synthesis-style: none; }

Result

Comparison of font-synthesis-style values

This example compares all the font-synthesis-style values using italic and oblique styled texts.

HTML

html

<div class="fss-none"> <h2>font-synthesis-style: none</h2> <p class="oblique">This text is set to <code>oblique</code></p> <p class="italic">This text is set to <code>italic</code></p> </div> <div class="fss-auto"> <h2>font-synthesis-style: auto</h2> <p class="oblique">This text is set to <code>oblique</code></p> <p class="italic">This text is set to <code>italic</code></p> </div> <div class="fss-oblique-only"> <h2>font-synthesis-style: oblique-only</h2> <p class="oblique">This text is set to <code>oblique</code></p> <p class="italic">This text is set to <code>italic</code></p> </div>

CSS

@import "https://fonts.googleapis.com/css2?family=Montserrat&display=swap"; p { font-family: "Montserrat", sans-serif; font-size: 1.2rem; } @supports not (font-synthesis-style: oblique-only) { body::before { content: "Your browser doesn't support the 'oblique-only' value."; background-color: #ffcd33; display: block; width: 100%; text-align: center; } }

css

/* Specify style of the font synthesis */ .fss-none { font-synthesis-style: none; } .fss-auto { font-synthesis-style: auto; } .fss-oblique-only { font-synthesis-style: oblique-only; } /* Set font styles */ .oblique { font-style: oblique; } .italic { font-style: italic; } /* Styles for the demonstration */ .oblique::after { content: " (font-style: oblique)"; font-size: 0.8rem; vertical-align: sub; } .italic::after { content: " (font-style: italic)"; font-size: 0.8rem; vertical-align: sub; }

Result

Specifications

Specification
CSS Fonts Module Level 4 # font-synthesis-style

Browser compatibility

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This page was last modified on ⁨Oct 30, 2025⁩ by MDN contributors.

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