TextMetrics: fontBoundingBoxDescent property

Baseline 2023
Newly available

Since August 2023, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.

Note: This feature is available in Web Workers.

The read-only fontBoundingBoxDescent property of the TextMetrics interface returns the distance from the horizontal line indicated by the CanvasRenderingContext2D.textBaseline attribute to the bottom of the bounding rectangle of all the fonts used to render the text, in CSS pixels.

Value

A number, in CSS pixels.

Examples

The code below shows how you can get the fontBoundingBoxDescent for text in a particular font.

js
const canvas = document.createElement("canvas");
const ctx = canvas.getContext("2d");

ctx.font = "25px serif";
const text = "Foo";

const textMetrics = ctx.measureText(text); // returns TextMetrics object
const descentCssPixels = textMetrics.fontBoundingBoxDescent;

The descent in CSS pixels for the text "Foo" in a 25px serif font is shown below.

Specifications

Specification
HTML
# dom-textmetrics-fontboundingboxdescent-dev

Browser compatibility

See also