Chart.ReferenceLine

A threshold or target across the plot.

JanFebMarAprMayJun01020304050Target
Chart of Projects published over 6 points
monthProjects published
January24
February31
March28
April35
May42
June38
<Chart.ReferenceLine value={30} label="Target" />

API

PropTypeDefault
categorystringThe category the line sits before: it runs along the leading edge of that category's slot, between it and the one before.
labelstringText drawn beside the line — a target, a threshold, an average.
strokeDasharraystring"4 4"Dash pattern for the line. Pass undefined for solid.
valuenumberPosition on the value axis.

Plus the DOM props of the element it renders. Source: chart/components/chart-reference-line.tsx.

value is on the value axis, so a reference line marks a threshold, a target or an average. Place it after the marks to draw it on top.

For a date, pass category instead: the line runs along the leading edge of that category's slot, which is where "today" belongs on a chart whose categories are days or weeks.

<Chart.ReferenceLine category="2026-09-21" label="Today" />