Line chart

Single-series line chart for continuous trend over an ordered domain.

line connects data points to show how a single measure changes across an ordered axis — typically time. It supports interpolation, lineSymbols, crosshair, and tooltips.

When to use

Showing trends, patterns, or changes over time
Continuous data where the order matters
Revealing rate of change — the slope communicates speed
A single series; readers focus on direction rather than precise totals

When NOT to use

Categorical data with no inherent order — lines imply sequence
When the cumulative magnitude matters more than the trend (use area)
When you want to compare two or more series (use line-multi)

Example

bpc

chart line {
  title = "2024 was the hottest year on record"
  description = "Deviation from the 1951–1980 average, in °C"
  source = "NASA GISS"
  sourceUrl = "https://data.giss.nasa.gov/gistemp/"
  colors = "#e15759"
  interpolation = "monotoneX"
  lineSymbols = true
  lineSymbolShowOn = "firstLast"
  tooltips = true

  data {
    "1980" = 0.26
    "1990" = 0.45
    "2000" = 0.42
    "2010" = 0.72
    "2020" = 1.02
    "2024" = 1.29
  }
}

Common pitfalls

Aggressively truncating the y-axis exaggerates small movements
Forcing the y-axis to start at zero when the data sits in a narrow band flattens the trend — unlike bars, line charts don't require a zero baseline
Smoothing with basis interpolation can overshoot the data; prefer monotoneX when fidelity matters

line-multi — when you need to compare two or more series on the same axes
area — when the magnitude of the value matters as much as the trend
bar-vertical — when the x-axis is categorical, not continuous

Line chart ​

When to use ​

When NOT to use ​

Example ​

Common pitfalls ​

Related types ​

See also ​

Line chart

When to use

When NOT to use

Example

Common pitfalls

Related types

See also