Set height of chart in Chart.js

javascript

responsive-design

performance

best-practices

byAnton Shumikhin·Nov 14, 2024

To fine-tune the height of a Chart.js chart, you can either use CSS directly on the canvas or tweak the chart options. If you prefer a static height, apply the CSS directly. But, in case you want to keep your chart responsive, set the maintainAspectRatio option in Chart.js to false.

CSS (Static Height):

#myChart {
    height: 400px; # 💥 fixed height, as fixed as your dedication to coding 💪
}

Chart.js (Responsive Height):

const chart = new Chart(ctx, {
    // ...
    options: {
        responsive: true, # 🚀 adapts like a chameleon to its surroundings
        maintainAspectRatio: false # 🤸‍♂️ performs gymnastics with responsive design
    }
});

CSS provides an instant solution for fixed-size, while chart options will be the go-to if your focus is on adaptable, responsive designs.

A step further: controlling with divs

If you are looking for a more granular control over your chart's height, you can wrap the canvas inside a div, and set a defined height to that div. If you're dealing with a responsive layout, this can give you precise control:

<div id="chartContainer" style="height: 400px; position: relative;">
    <canvas id="myChart"></canvas>
</div>

For horizontal bar charts, making optimal use of the viewport height is paramount. Here, setting maintainAspectRatio to false allows the chart to adjust its height while keeping its width intact.

When working with multiple charts each with their different heights, remember to treat them like your precious little tamagotchis, each with its own unique ID! So, always give them distinct canvas IDs and set the CSS or JS accordingly.

Adapting to responsiveness

Responsive designs are all about adaptability. So, if you want your chart height to adapt to varying screen sizes, use relative CSS units like vh or %.

#chartContainer {
    height: 50vh; /* 👀 keeps an eye on the viewport size */
}

Don't forget: if you are setting the height in an external CSS, ensure it doesn't lead a rebellion against your styles! Keep the specificity of your CSS higher than any default styles to prevent conflicts.

Pitfalls sighted along the road

Keep responsive option set to true. It tells Chart.js to play nice with the rest of the playground.
Trying to set the canvas height attribute directly via JavaScript might reset the chart. Opt for applying dimensions via CSS or the chart's options. The latter is your ticket for the dynamic resizing party.
Got jQuery? Be careful with your selectors! Verify the canvas ID by using $('#myChart') when adjusting height.
It's always a good idea to taste test different CSS units and values within a jsfiddle or CodePen playground.

Setting Chart Height in Chart.js:

Short Chart	Taller Chart

  🕹️    |       🎮

(Short Game) | (Tall Game)


**Code to Adjust Height:**

```javascript
chartInstance.chart.height = 400; // 🕹️➡️🎮 It's quite an upgrade!

With Chart.js, your chart height levels up just as you like it! 📈🎮

Styling, positioning, and the final touch

Your charts will need to be on point, just like your fashion sense. For this, use CSS positioning properties on the parent div for precise layout control.

For fine-tuning the responsiveness, don't hesitate to mix vh and px units when specifying chart height. It's like making the perfect cocktail, except it's for layouts!

#chartContainer {
    height: 50vh; /* Responsive height, adds the zing */
    min-height: 300px; /* No more shrinkage, adds the strength */
}

Keep in mind, accessibility can't be an afterthought. Always ensure compatibility across different devices and browsers while setting your chart heights.

explain-codes / Javascript / Set height of chart in Chart.js

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