# The HTML-CSS output processor¶

The options below control the operation of the HTML-CSS output processor that is run when you include "output/HTML-CSS" in the jax array of your configuration or load a combined configuration file that includes the HTML-CSS output jax. They are listed with their default values. To set any of these options, include a "HTML-CSS" section in your MathJax.Hub.Config() call. Note that, because of the dash, you need to enclose the name in quotes. For example

MathJax.Hub.Config({
"HTML-CSS": {
preferredFont: "STIX"
}
});


would set the preferredFont option to the STIX fonts.

scale: 100

The scaling factor (as a percentage) of math with respect to the surrounding text. The HTML-CSS output processor tries to match the ex-size of the mathematics with that of the text where it is placed, but you may want to adjust the results using this scaling factor. The user can also adjust this value using the contextual menu item associated with the typeset mathematics.

minScaleAdjust: 50

This gives a minimum scale (as a percent) for the scaling used by MathJax to match the equation to the surrounding text. This will prevent MathJax from making the mathematics too small.

availableFonts: ["STIX","TeX"]

This is a list of the fonts to look for on a user’s computer in preference to using MathJax’s web-based fonts. These must correspond to directories available in the jax/output/HTML-CSS/fonts directory, where MathJax stores data about the characters available in the fonts. Set this to ["TeX"], for example, to prevent the use of the STIX fonts, or set it to an empty list, [], if you want to force MathJax to use web-based or image fonts.

preferredFont: "TeX"

Which font to prefer out of the availableFonts list, when more than one is available on the user’s computer. Set it to null if you want MathJax to use web-based or image fonts.

webFont: "TeX"

This is the web-based font to use when none of the fonts listed above are available on the user’s computer. The possible values are TeX, STIX-Web, Asana-Math, Neo-Euler, Gyre-Pagella, Gyre-Termes and Latin-Modern. Note that not all mathematical characters are available in all fonts (e.g., Neo-Euler does not include italic characters), so some mathematics may work better in some fonts than in others. The STIX-Web font is the most complete.

These fonts are stored in the fonts/HTML-CSS folder in the MathJax directory. Set this to null to disable web fonts.

imageFont: "TeX"

This is the font to use for image fallback mode (when none of the fonts listed above are available and the browser doesn’t support web-fonts via the @font-face CSS directive). Note that currently only the TeX font is available as an image font (they are stored in the fonts/HTML-CSS directory).

Set this to null if you want to prevent the use of image fonts (e.g., you have deleted or not installed the image fonts on your server). In this case, only browsers that support web-based fonts will be able to view your pages without having the fonts installed on the client computer. The browsers that support web-based fonts include: IE6 and later, Chrome, Safari3.1 and above, Firefox3.5 and later, and Opera10 and later. Note that Firefox3.0 is not on this list.

undefinedFamily: "STIXGeneral, 'Arial Unicode MS', serif"

This is the font-family CSS value used for characters that are not in the selected font (e.g., for web-based fonts, this is where to look for characters not included in the MathJax web fonts). IE will stop looking after the first font that exists on the system (even if it doesn’t contain the needed character), so order these carefully.

mtextFontInherit: false

This setting controls whether <mtext> elements will be typeset using the math fonts or the font of the surrounding text. When false, the font for mathvariant="normal" will be used; when true, the font will be inherited from the surrounding paragraph.

EqnChunk: 50
EqnChunkFactor: 1.5
EqnChunkDelay: 100

These values control how “chunky” the display of mathematical expressions will be; that is, how often the equations will be updated as they are processed.

EqnChunk is the number of equations that will be typeset before they appear on screen. Larger values make for less visual flicker as the equations are drawn, but also mean longer delays before the reader sees anything.

EqChunkFactor is the factor by which the EqnChunk will grow after each chunk is displayed.

EqChunkDelay is the time (in milliseconds) to delay between chunks (to allow the browser to respond to other user interaction).

Set EqnChunk to 1, EqnChunkFactor to 1, and EqnChunkDelay to 10 to get the behavior from MathJax v1.1 and below.

matchFontHeight: true

This option indicates whether MathJax should try to adjust the x-height of equations to match the x-height of the surrounding text. See the MatchWebFonts options for finer control, especially if you are using Web fonts.

linebreaks: {}

This is an object that configures automatic linebreaking in the HTML-CSS output. In order to be backward compatible with earlier versions of MathJax, only explicit line breaks are performed by default, so you must enable line breaks if you want automatic ones. The object contains the following values:

automatic: false

This controls the automatic breaking of expressions: when false, only linebreak="newline" is processed; when true, line breaks are inserted automatically in long expressions.

width: "container"

This controls how wide the lines of mathematics can be.

Use an explicit width like "30em" for a fixed width. Use "container" to compute the size from the containing element. Use "nn% container" for a portion of the container. Use "nn%" for a portion of the window size.

The container-based widths may be slower, and may not produce the expected results if the layout width changes due to the removal of previews or inclusion of mathematics during typesetting.

styles: {}

This is a list of CSS declarations for styling the HTML-CSS output. See the definitions in jax/output/HTML-CSS/config.js for some examples of what are defined by default. See CSS Style Objects for details on how to specify CSS style in a JavaScript object.

showMathMenu: true

This value has been moved to the core configuration block, since it applies to all output jax, but it will still be honored (for now) if it is set here. See the Core configuration options for more details.

tooltip: { ... }

This sets the configuration options for <maction> elements with actiontype="tooltip". (See also the #MathJax_Tooltip style setting in jax/output/HTML-CSS/config.js, which can be overridden using the styles option above.)

The tooltip section can contain the following options:

delayPost: 600

The delay (in milliseconds) before the tooltip is posted after the mouse is moved over the maction element.

delayClear: 600

The delay (in milliseconds) before the tooltop is cleared after the mouse moves out of the maction element.

offsetX: 10
offsetY: 5

These are the offset from the mouse position (in pixels) where the tooltip will be placed.

noReflows: true

This value determines if the HTML-CSS output makes additional measurements during layout for better layout quality, in particular with respect to unknown Unicode characters. As these measurements require reflow setting this to false will reduce performance but can help resolve layout issues.