alignment-baseline property

Specifies which baseline of this element is to be aligned with the corresponding baseline of the parent.

This property is read/write.

Scalable Vector Graphics: Text, Section 10.9.2Internet Explorer 10



alignment-baseline: auto | baseline | before-edge | text-before-edge | middle | central | after-edge | text-after-edge | ideographic | alphabetic | hanging | mathematical | inherit

Property values

One of the following values:


Align with the dominant-baseline of the parent.


Align with the dominant-baseline of the parent text content element.


Same as text-before-edge.


Align with the before-edge of the parent's EM box. The position of this baseline is normally around or at the top of the ascenders, but it may not encompass all accents that can appear above a glyph.


Align with a point half-way between the alphabetic baseline and the value of the x-height font characteristic.


Align with the center of the parent's EM box. This baseline lies halfway between the text-before-edge and text-after-edge baselines.


Same as text-after-edge.


Align with the after-edge of the parent's EM box. For fonts with descenders, the position of this baseline is normally around or at the bottom of the descenders.


Align with the baseline used by ideographic scripts, such as Chinese Simplified, Japanese, and Vietnamese Chu Nom. For historical reasons, this baseline is at the bottom of the ideographic EM box and not in the center of the ideographic EM box.


Align with the baseline used by most alphabetic and syllabic scripts.


Align with the baseline used by certain Indic scripts, such as Devanagari, Gurmukhi and Bangla.


Align with the baseline used by mathematical symbols.


Use the computed value of this property from an ancestor element.

CSS information

Applies To‘tspan’, ‘tref’, ‘altGlyph’, ‘textPath’ elements
Initial Valueauto

Standards information


As of Microsoft Edge, this presentation attribute is animatable with CSS Animations and CSS Transitions.

This property specifies how an object is aligned with respect to its parent. For example, this allows alphabetic baselines in Roman text to stay aligned across font size changes. It defaults to the baseline with the same name as the computed value of the alignment-baseline property. That is, the position of "ideographic" alignment-point in the block-progression-direction is the position of the "ideographic" baseline in the baseline-table of the object being aligned.

One of the characteristics of international text is that there are different baselines (different alignment points) for glyphs in different scripts. For example, in horizontal writing, ideographic scripts, such as Han Ideographs, Katakana, Hiragana, and Hangul, alignment occurs with a baseline near the bottoms of the glyphs; alphabetic based scripts, such as Latin, Cyrillic, Hebrew, Arabic, align a point that is the bottom of most glyphs, but some glyphs descend below the baseline; and Indic based scripts are aligned at a point that is near the top of the glyphs.

The "EM box" is a relative measure of the height of the glyphs in the font. The "M" character fits in a box 1 EM high and 1 EM wide.

See also