CanvasRenderingContext2D: textRendering property
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
TheCanvasRenderingContext2D.textRendering property of theCanvas API provides information to the rendering engine about what to optimize for when rendering text.
The values correspond to the SVGtext-rendering attribute (and CSStext-rendering property).
In this article
Value
A text-rendering hint to the browser engine.This one of:
autoThe browser makes educated guesses about when to optimize for speed, legibility, and geometric precision while drawing text.
optimizeSpeedThe browser emphasizes rendering speed over legibility and geometric precision when drawing text.It disables kerning and ligatures.
optimizeLegibilityThe browser emphasizes legibility over rendering speed and geometric precision.This enables kerning and optional ligatures.
geometricPrecisionThe browser emphasizes geometric precision over rendering speed and legibility.Certain aspects of fonts — such as kerning — don't scale linearly.For large scale factors, you might see less-than-beautiful text rendering, but the size is what you would expect (neither rounded up nor down to the nearest font size supported by the underlying operating system).
The property can be used to get or set the value.
Examples
In this example we display the text "Hello World" using each of the supported values of thetextRendering property.The value is also displayed for each case by reading the property.
HTML
<canvas width="700" height="220"></canvas>JavaScript
const canvas = document.getElementById("canvas");const ctx = canvas.getContext("2d");ctx.font = "20px serif";// Default (auto)ctx.fillText(`Hello world (default: ${ctx.textRendering})`, 5, 20);// Text rendering: optimizeSpeedctx.textRendering = "optimizeSpeed";ctx.fillText(`Hello world (${ctx.textRendering})`, 5, 50);// Text rendering: optimizeLegibilityctx.textRendering = "optimizeLegibility";ctx.fillText(`Hello world (${ctx.textRendering})`, 5, 80);// Text rendering: geometricPrecisionctx.textRendering = "geometricPrecision";ctx.fillText(`Hello world (${ctx.textRendering})`, 5, 110);Result
Specifications
| Specification |
|---|
| HTML> # dom-context-2d-textrendering> |