Chart.js is an free JavaScript library for making HTML-based charts. It is one of the simplest visualization libraries for JavaScript, and comes with the many built-in chart types:
- Scatter Plot
- Line Chart
- Bar Chart
- Pie Chart
- Donut Chart
- Bubble Chart
- Area Chart
- Radar Chart
- Mixed Chart
How to Use Chart.js?
- Add a link to the providing CDN (Content Delivery Network):
<script
src="https://cdn.jsdelivr.net/npm/chart.js@4.5.0">
</script>- Add a <canvas> to where in the HTML you want to draw the chart:
<canvas>
id="myChart" style="width:100%;max-width:700px"
</canvas>The canvas element must have a unique id.
const myChart = new Chart("myChart", {
type: "bar",
data: {},
options: {}
});const myChart = new Chart("myChart", {
type: "line",
data: {},
options: {}
});Bar Charts
Source Code
const xValues = ["Italy", "France", "Spain", "USA", "Argentina"];
const yValues = [55, 49, 44, 24, 15];
const barColors = ["red", "green","blue","orange","brown"];
new Chart("myChart", {
type: "bar", data: {
labels: xValues, datasets: [{
backgroundColor: barColors, data: yValues
}]
}, options: {...}
});Runnable example
const barColors = ["blue"];Runnable example
const barColors = [ "rgba(0,0,255,1.0)", "rgba(0,0,255,0.8)", "rgba(0,0,255,0.6)", "rgba(0,0,255,0.4)", "rgba(0,0,255,0.2)", ];indexAxis: 'y',Pie Charts
new Chart("myChart", {
type: "pie",
data: {
labels: xValues,
datasets: [{
backgroundColor: barColors,
data: yValues
}]
},
options: {
title: {
display: true,
text: "World Wide Wine Production"
}
}
});Doughnut Charts
type: "doughnut";Scatter Plots
House Prices vs. Size
Source Code
const xyValues = [ {x:50, y:7}, {x:60, y:8}, {x:70, y:8}, {x:80, y:9}, {x:90, y:9}, {x:100, y:9}, {x:110, y:10}, {x:120, y:11}, {x:130, y:14}, {x:140, y:14}, {x:150, y:15}
];
new Chart("myChart", {
type: "scatter", data: {
datasets: [{
pointRadius: 4, pointBackgroundColor: "rgba(0,0,255,1)", data: xyValues
}]
}, options:{...}
});Line Graphs
House Prices vs. Size
Source Code
const xValues = [50,60,70,80,90,100,110,120,130,140,150];
const yValues = [7,8,8,9,9,9,10,11,14,14,15];
new Chart("myChart", {
type: "line", data: {
labels: xValues, datasets: [{
backgroundColor:"rgba(0,0,255,1.0)", borderColor: "rgba(0,0,255,0.1)", data: yValues
}]
}, options:{...}
});If you set the borderColor to zero, you can scatter plot the line graph:
borderColor: "rgba(0,0,0,0)",Multiple Lines
Source Code
const xValues = [100,200,300,400,500,600,700,800,900,1000];
new Chart("myChart", {
type: "line", data: {
labels: xValues, datasets: [{
data: [860,1140,1060,1060,1070,1110,1330,2210,7830,2478], borderColor: "red", fill: false
},{
data: [1600,1700,1700,1900,2000,2700,4000,5000,6000,7000], borderColor: "green", fill: false
},{
data: [300,700,2000,5000,6000,4000,2000,1000,200,100], borderColor: "blue", fill: false
}]
}, options: {
legend: {display: false}
}
});Linear Graphs
Source Code
const xValues = [];
const yValues = [];
generateData("x * 2 + 7", 0, 10, 0.5);
const ctx = document.getElementById('myChart');
new Chart(ctx, {
type: "line", data: {
labels: xValues, datasets: [{
fill: false, pointRadius: 1, borderColor: "rgba(255,0,0,0.5)", data: yValues
}]
}, options: {...}
});
function generateData(value, i1, i2, step = 1) {
for (let x = i1; x <= i2; x += step) {
yValues.push(eval(value));
xValues.push(x);
}
}Function Graphs
generateData("Math.sin(x)", 0, 10, 0.5);