A line plot with the area between the line and the baseline (typically x-axis) filled with a semi-transparent color. This creates an area chart effect for a single series, emphasizing the magnitude of values.

// anyplot.ai
// line-filled: Filled Line Plot
// Library: highcharts 12.6.0 | JavaScript 22.23.2
// Quality: 84/100 | Created: 2026-09-05
const t = window.ANYPLOT_TOKENS;
// --- Data (in-memory, deterministic — daily reservoir level over 30 days) --
function lcg(seed) {
let state = seed;
return () => {
state = (state * 1664525 + 1013904223) % 4294967296;
return state / 4294967296;
};
}
const rand = lcg(42);
const days = Array.from({ length: 30 }, (_, i) => i);
const levels = [];
let level = 42;
for (let i = 0; i < days.length; i++) {
level += (rand() - 0.42) * 4;
level = Math.max(20, level);
levels.push(Math.round(level * 10) / 10);
}
// --- Chart -------------------------------------------------------------------
Highcharts.chart("container", {
chart: {
type: "area",
backgroundColor: "transparent",
animation: false,
style: { fontFamily: "inherit" },
},
credits: { enabled: false },
colors: t.palette,
title: {
text: "Reservoir Water Level · line-filled · javascript · highcharts · anyplot.ai",
style: { color: t.ink, fontSize: "22px", fontWeight: "600" },
},
xAxis: {
title: { text: "Day", style: { color: t.inkSoft, fontSize: "16px" } },
lineColor: t.inkSoft,
tickColor: t.inkSoft,
gridLineColor: t.grid,
categories: days.map(String),
tickInterval: 5,
labels: { style: { color: t.inkSoft, fontSize: "14px" } },
},
yAxis: {
title: { text: "Water Level (m)", style: { color: t.inkSoft, fontSize: "16px" } },
min: 0,
gridLineColor: t.grid,
labels: { style: { color: t.inkSoft, fontSize: "14px" } },
},
legend: { enabled: false },
tooltip: {
backgroundColor: t.elevatedBg,
borderColor: t.grid,
style: { color: t.ink, fontSize: "13px" },
headerFormat: "Day {point.key}<br/>",
pointFormat: "Water Level: <b>{point.y} m</b>",
},
plotOptions: {
series: { animation: false },
area: {
lineWidth: 2.5,
color: t.palette[0],
fillColor: {
linearGradient: { x1: 0, y1: 0, x2: 0, y2: 1 },
stops: [
[0, t.palette[0] + "8C"],
[1, t.palette[0] + "21"],
],
},
marker: { enabled: true, radius: 3, fillColor: t.palette[0], lineWidth: 0 },
threshold: 0,
},
},
series: [{ name: "Water Level", data: levels }],
});
Runnable source as JSON, for any HTTP client: https://api.anyplot.ai/specs/line-filled/highcharts/code. Any spec id and library id listed in llms-full.txt fit the same URL shape; every URL below is complete and callable.
{
"spec_id": "line-filled",
"language": "javascript",
"library": "highcharts",
"page": "https://anyplot.ai/line-filled/javascript/highcharts",
"hub": "https://anyplot.ai/line-filled",
"code_json": "https://api.anyplot.ai/specs/line-filled/highcharts/code",
"spec_json": "https://api.anyplot.ai/specs/line-filled",
"render_light_png": "https://storage.googleapis.com/anyplot-images/plots/line-filled/javascript/highcharts/plot-light.png",
"render_dark_png": "https://storage.googleapis.com/anyplot-images/plots/line-filled/javascript/highcharts/plot-dark.png",
"interactive_light_html": "https://storage.googleapis.com/anyplot-images/plots/line-filled/javascript/highcharts/plot-light.html",
"interactive_dark_html": "https://storage.googleapis.com/anyplot-images/plots/line-filled/javascript/highcharts/plot-dark.html",
"quality_score": 84.0,
"license": "MIT",
"guide": "https://anyplot.ai/llms.txt"
}Part of Filled Line Plot on anyplot.ai.