Understanding how to control axes and scales is essential for creating effective data visualizations with Chart.js. The axes of a chart provide context for your data, so configuring them correctly ensures your charts are both accurate and easy to read. In Chart.js, you can choose from several axis types, each suited to different kinds of data. The category axis is ideal for discrete labels, such as names or months, and is commonly used for the x-axis in bar or line charts. The linear axis is designed for numerical data with equal intervals, making it perfect for continuous values like measurements, scores, or time-series data. When your data spans several orders of magnitude, the logarithmic axis helps by compressing large ranges and revealing patterns that might be hidden with a linear scale.

Configuring scales in Chart.js involves specifying the type of axis, its minimum and maximum values, and how ticks (the axis labels) are displayed. You can customize the ticks to show specific formatting, such as adding units or rounding values. Additionally, grid lines—those horizontal and vertical lines that cross the chart background—can be styled to match your design needs. Customizing grid line color, width, and dash pattern can improve readability and visual appeal.