Multi-line chart

Multi-series line chart for comparing several time series or trends.

line-multi plots two or more series on shared axes so readers can see divergence, convergence, and ranking shifts over an ordered domain. Supports interpolation, lineSymbols, crosshair, and tooltips.

When to use

• Comparing trends across 2–4 series on the same scale
• Showing divergence or convergence between groups over time
• Highlighting one key series against grey "context" lines

When NOT to use

• More than 5–6 series — the chart becomes a spaghetti tangle
• Series with very different scales (avoid dual axes; consider small multiples instead)
• Composition over time, where readers need to see how parts add up (use area-stacked)

Example

chart line-multi {
  title = "Germany stagnated while the US and China bounced back"
  description = "Annual percentage change in real GDP"
  source = "IMF World Economic Outlook"
  sourceUrl = "https://imf.org"
  colorPalette = "SolLeWitt"
  legend = false
  tooltips = true

  data {
    _series = "United States","China","Germany"
    "2018" = 2.9,6.7,1.0
    "2019" = 2.3,6.0,1.1
    "2020" = -2.8,2.2,-3.7
    "2021" = 5.9,8.4,3.2
    "2022" = 2.1,3.0,1.8
    "2023" = 2.5,5.2,-0.1
    "2024" = 2.8,5.0,-0.2
  }
}

Common pitfalls

• Five or more lines crossing each other defeats the chart — either highlight one and grey the rest, or split into small multiples
• Two y-axes with different scales imply a correlation that may not exist
• Inconsistent colour assignment between charts in the same story confuses readers

Related types

• line — when you only need a single series
• area-stacked — when the running total across series matters
• bar-grouped — when the x-axis is categorical, not continuous

See also

• Choosing the right chart
• Design principles