CanvasRenderingContext2D: fontKerning property
The CanvasRenderingContext2D.fontKerning property of the Canvas API specifies how font kerning information is used.
Kerning adjusts how adjacent letters are spaced in a proportional font, allowing them to edge into each other's visual area if there is space available.
For example, in well-kerned fonts, the characters AV, Ta and We nest together and make character spacing more uniform and pleasant to read than the equivalent text without kerning.
The property corresponds to the font-kerning CSS property.
Value
The property can be used to get or set the value.
Allowed values are:
auto-
The browser determines whether font kerning should be used or not. For example, some browsers will disable kerning on small fonts, since applying it could harm the readability of text.
normal-
Font kerning information stored in the font must be applied.
none-
Font kerning information stored in the font is disabled.
Examples
In this example we display the text "AVA Ta We" using each of the supported values of the textRendering property.
HTML
<canvas id="canvas" width="700" height="140"></canvas>
JavaScript
const canvas = document.getElementById("canvas");
const ctx = canvas.getContext("2d");
ctx.font = "30px serif";
// Default (auto)
ctx.fillText(`AVA Ta We (default: ${ctx.fontKerning})`, 5, 30);
// Font kerning: normal
ctx.fontKerning = "normal";
ctx.fillText(`AVA Ta We (${ctx.fontKerning})`, 5, 70);
// Font kerning: none
ctx.fontKerning = "none";
ctx.fillText(`AVA Ta We (${ctx.fontKerning})`, 5, 110);
Result
Note that the last string has font kerning disabled, so adjacent characters are evenly spread.
Specifications
| Specification |
|---|
| HTML Standard # dom-context-2d-fontkerning |
Browser compatibility
BCD tables only load in the browser