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CanvasRenderingContext2D.textBaseline

The CanvasRenderingContext2D.textBaseline property of the Canvas 2D API specifies the current text baseline being used when drawing text.

Syntax

ctx.textBaseline = "top" || "hanging" || "middle" || "alphabetic" || "ideographic" || "bottom";

Options

Possible values:

top
The text baseline is the top of the em square.
hanging
The text baseline is the hanging baseline. (Used by Tibetan and other Indic scripts.)
middle
The text baseline is the middle of the em square.
alphabetic (default value)
The text baseline is the normal alphabetic baseline.
ideographic
The text baseline is the ideographic baseline; this is the bottom of the body of the characters, if the main body of characters protrudes beneath the alphabetic baseline. (Used by Chinese, Japanese and Korean scripts.)
bottom
The text baseline is the bottom of the bounding box. This differs from the ideographic baseline in that the ideographic baseline doesn't consider descenders.

The default value is alphabetic.

Examples

Using the textBaseline property

This demonstrates the different textBaseline property values.

HTML

<canvas id="canvas" width="550" height="500"></canvas>

JavaScript

var canvas = document.getElementById('canvas');
var ctx = canvas.getContext('2d');

var baselines = ['top', 'hanging', 'middle', 'alphabetic', 'ideographic', 'bottom'];
ctx.font = '36px serif';
ctx.strokeStyle = 'red';

baselines.forEach(function (baseline, index) {
    ctx.textBaseline = baseline;
    var y = 75 + index * 75;
    ctx.beginPath(); ctx.moveTo(0, y + 0.5); ctx.lineTo(550, y + 0.5); ctx.stroke();
    ctx.fillText('Abcdefghijklmnop (' + baseline + ')', 0, y);
});

Edit the code below and see your changes update live in the canvas:

Specifications

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari
Basic support (Yes) (Yes) 3.5 (1.9.1) 9 (Yes) (Yes)
Feature Android Chrome for Android Edge Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support (Yes) (Yes) (Yes) 1.0 (1.9.1) (Yes) (Yes) (Yes)

See also

© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/textBaseline