Plot 40,840 's defaults make it the faster tool for exploring data and for standard charts; D3 18,089 remains the tool when the chart itself is the product:
| Need | Plot | D3 |
|---|---|---|
| Animated transitions | No; each call redraws | d3-transition (Transitions) |
| Zoom, brush, drag | Pointer and tips only | d3-zoom, d3-brush, d3-drag |
| Custom layouts | Built-in marks, tree | Any hierarchy or force layout |
| Canvas for big data | SVG output | Canvas Rendering |
The two mix: Plot's output is plain SVG you can d3.select to add a transition or a brush. Plot is pre-1.0, so pin its version.
<!doctype html>
<style>
body { margin: 0; padding: 8px; background: #fafaf7; font: 12px system-ui, sans-serif; color: #263238; }
#out { font-size: 13px; font-weight: bold; }
</style>
<script src="https://cdn.jsdelivr.net/npm/d3@7.9.0/dist/d3.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/@observablehq/plot@0.6.17/dist/plot.umd.min.js"></script>
<div id="chart"></div>
<p id="out"></p>
<p>Plot for the standard chart (scales, axes, bars); D3 for the interaction: drag across the bars.</p>
<script>
// BookNest sample data, invented for these examples (not real sales)
const SALES = (() => {
const books = [
{ id: 1, key: 'harbor', title: 'The Quiet Harbor', author: 'Elena Marsh', genre: 'Fiction', color: '#1f5f8b', price: 18.99, rating: 4.6 },
{ id: 2, key: 'deepweb', title: 'Patterns of the Deep Web', author: 'Ravi Menon', genre: 'Technology', color: '#5b3f99', price: 39.5, rating: 4.3 },
{ id: 3, key: 'saffron', title: 'Salt and Saffron', author: 'Leila Haddad', genre: 'Cooking', color: '#e09a10', price: 24, rating: 4.8 },
{ id: 4, key: 'summit', title: 'Small Steps to Big Summits', author: 'Tom Okafor', genre: 'Self-Help', color: '#3f7d3a', price: 14.99, rating: 4.1 },
{ id: 5, key: 'clock', title: "The Clockmaker's Paradox", author: 'Iris Vale', genre: 'Science Fiction', color: '#b5452f', price: 16.2, rating: 4.5 },
{ id: 6, key: 'glass', title: 'Gardens in Glass', author: 'June Park', genre: 'Gardening', color: '#2a9d8f', price: 22.5, rating: 4.4 },
];
const units = { // units sold per month, January 2025 to August 2026
1: [40, 47, 46, 47, 57, 51, 46, 54, 60, 60, 71, 111, 52, 42, 49, 56, 59, 48, 53, 51],
2: [40, 37, 35, 41, 48, 43, 40, 42, 50, 53, 53, 84, 42, 35, 38, 41, 45, 41, 46, 46],
3: [46, 45, 41, 46, 53, 49, 46, 45, 60, 51, 63, 100, 48, 48, 49, 48, 53, 49, 48, 52],
4: [100, 80, 72, 70, 66, 66], // released March 2026
5: [48, 47, 54, 52, 65, 55, 57, 58, 64, 66, 75, 124, 58, 49, 59, 56, 63, 57, 54, 57],
6: [31, 30, 28, 35, 31, 32, 29, 30, 41, 36, 45, 64, 31, 30, 30, 38, 40, 38, 36, 38],
};
const months = d3.utcMonths(new Date('2025-01-01'), new Date('2026-09-01')).map(d3.utcFormat('%Y-%m'));
const sales = books.flatMap(b => units[b.id].map((n, i) =>
({ month: months[i + months.length - units[b.id].length], book: b.id, units: n })));
const ratings = [[4, 8, 20, 87, 293], [6, 10, 22, 95, 147], [2, 3, 8, 45, 342], [2, 3, 8, 24, 28],
[4, 8, 20, 90, 228], [4, 7, 20, 82, 147]].map((counts, i) => ({ book: i + 1, counts })); // 1 to 5 stars
const regions = [{ id: '826', name: 'United Kingdom', units: 1480 }, { id: '276', name: 'Germany', units: 1120 },
{ id: '250', name: 'France', units: 760 }, { id: '372', name: 'Ireland', units: 540 },
{ id: '528', name: 'Netherlands', units: 410 }, { id: '724', name: 'Spain', units: 320 }];
const links = [[5, 1, 38], [1, 3, 24], [2, 5, 18], [3, 6, 21], [4, 1, 12], [2, 6, 9], [4, 3, 15], [5, 6, 14]]
.map(([source, target, value]) => ({ source, target, value })); // customers who bought both
return { books, sales, ratings, regions, links };
})();
// prepareSales(raw): parsed dates, sales linked to book objects, revenue and totals
function prepareSales(raw) {
const parse = d3.utcParse('%Y-%m'), books = raw.books.map(b => ({ ...b }));
const byId = d3.index(books, b => b.id);
const sales = raw.sales.map(s => ({ date: parse(s.month), book: byId.get(s.book),
units: s.units, revenue: s.units * byId.get(s.book).price }));
for (const [book, rows] of d3.group(sales, s => s.book)) {
book.units = d3.sum(rows, s => s.units);
book.revenue = d3.sum(rows, s => s.revenue);
}
const months = d3.rollups(sales, v => ({ units: d3.sum(v, s => s.units),
revenue: d3.sum(v, s => s.revenue) }), s => +s.date).map(([t, v]) => ({ date: new Date(t), ...v }))
.sort((a, b) => a.date - b.date);
const ratings = raw.ratings.map(r => ({ ...r, book: byId.get(r.book) }));
return { ...raw, books, sales, months, ratings };
}
const { months } = prepareSales(SALES);
// 1. Plot: the whole chart in one call, with axes and scales inferred
const chart = Plot.plot({ width: 580, height: 190, y: { grid: true, label: 'Units per month' },
marks: [Plot.rectY(months, { x: 'date', y: 'units', interval: 'month', fill: '#b0bec5', insetLeft: 1 }), Plot.ruleY([0])] });
document.getElementById('chart').append(chart);
// 2. D3: Plot's output is plain SVG, so d3.select can add a brush; chart.scale('x') is the same scale
const x = chart.scale('x'), svg = d3.select(chart);
const bars = svg.selectAll('rect').filter(function () { return this.parentNode.getAttribute('aria-label') === 'rect'; });
const brush = d3.brushX().extent([[x.range[0], 10], [x.range[1], 160]]).on('brush end', ({ selection }) => {
const [a, b] = selection ? selection.map(px => d3.utcMonth.round(x.invert(px))) : [0, 0];
const picked = months.filter(m => m.date >= a && m.date < b);
bars.transition().duration(150).attr('fill', (d, i) => picked.includes(months[i]) ? '#e09a10' : '#b0bec5');
d3.select('#out').text(selection ? `${picked.length} months selected: ${d3.sum(picked, m => m.units)} units, ` +
`${d3.format('$,.0f')(d3.sum(picked, m => m.revenue))}` : 'no selection');
});
svg.append('g').call(brush).call(brush.move, [x.apply(new Date('2025-09-01')), x.apply(new Date('2026-01-01'))]);
</script>