Core Components

• color — default palette, applied to series in order.
• animation — disable for live/streaming charts.
• useUTC — interpret times as UTC vs local.

darkMode

• Values: "auto" (default), true, false.
• "auto" — ECharts inspects backgroundColor and flips internal defaults (axis label color, splitLine color, etc.) so text stays readable on dark canvases. If you set backgroundColor to a dark color, you usually don’t need to set darkMode explicitly.
• true / false — force the mode regardless of background. Useful when:
  • You render against a transparent background but the host app is dark themed.
  • You’re embedding multiple charts and want consistent text colors independent of each background.
• Mostly used by theme presets — most app code can leave it on "auto".

xAxis / yAxis

Multi-axis: pass an array of two axis objects. Series picks one via yAxisIndex: 1.

tooltip

For multi-series, prefer trigger: 'axis'. For pie/scatter, trigger: 'item'. formatter accepts template strings ({a} series, {b} name, {c} value, {d} percent) or a JS function string; the renderer must eval function strings under its safety policy, so prefer templates or valueFormatter.

legend

grid — chart drawing area inside the canvas

Set containLabel: true whenever axis labels rotate or get long — otherwise labels clip at the canvas edge.

dataZoom

Two flavors, often used together:

visualMap — drives color mapping

Continuous:

Required for heatmap and useful for any series that colors by value. Piecewise buckets and diverging palettes: patterns/color-themes-and-visualmap.md.

dataset — declarative data source (preferred over inlining series.data)

With dataset, series map columns automatically; use encode to pick columns explicitly. Use this whenever data exceeds ~200 inline points.

title

toolbox