funnel

EvidenceCanvasSeries

Tapering stages that show where a flow drops off, with the conversion rate between each.

Use for a pipeline that narrows — a sales / conversion funnel, a hiring or grant pipeline, an onboarding flow. Each stage's band width is proportional to its value; the stage-to-stage conversion % is printed in the gaps so the leak is the read.

percentagesequencepitch

When to use

The story is the drop-off. A funnel earns its shape when each stage is a strict subset of the one above and the audience needs to see WHERE the flow narrows — the leaky step, not just the totals. If the stages aren't a shrinking pipeline, use progress or stats.
Three to seven stages. Two stages is just a ratio (use big-number or stats); past seven the bands thin out and the conversion labels crowd. Most pipelines fit in four to six.
Values in flow order, widest first. Author the stages top-to-bottom as the flow runs, largest count first. The widest value sets full width and every band scales to it; the conversion % is computed from each value to the next.

When not to use

Stages that aren't a subset. If a later stage can exceed an earlier one (it's a category breakdown, not a pipeline), the taper lies. Use piechart for parts of a whole or progress for independent metrics.
A funnel of two stages. Two bands is a single conversion rate dressed up as a chart. State it as a big-number (‘18% convert’) or a two-tile stats instead.
Non-monotonic values. Values that rise and fall make the trapezoids bulge and the conversion %s read oddly. A funnel assumes a monotonic narrowing; for an up-and-down series use a progress or a chart with an axis.

Common mistakes

Assuming the detail sublist appears somewhere visible on the printed chart face. Detail bullets render NOWHERE on the chart itself — they drive a hover/tap reveal popover on screen and fold into the PDF's speaker note; a funnel with detail bullets looks pixel-identical to one without on the printed page.

Authoring

<!-- _class: funnel -->

## Where the flow drops off.

- First stage `1000`
- Second stage `600`
- Third stage `320`
- Fourth stage `140`

Slots

Slot	Selector	Required	Description
`title`	`h2`	yes	Slide heading — name the flow and, ideally, the takeaway (‘Where the pipeline leaks’).
`stages`	`ul > li`	yes	One li per stage, in flow order (widest first). Lead with the stage label, then a trailing inline-code value — `Signups \`4,800\``. Commas and units are tolerated; the largest value sets full width. Three to seven stages read best.
`detail`	`li > ul`	no	Optional nested sublist under a stage. Drives two surfaces from one source (shared with pie/map/quadrant via the chart-family mark-detail substrate): (1) Present/Practice — the kernel tags the stage `<polygon>` with `data-mark` and emits the sublist as an inert `<template class="chart-detail">` the reveal layer reads; (2) the static PDF — the same detail is folded into the slide's speaker note (`Label (value): item · item`) as a Marp-faithful comment that notes-core lifts into the per-slide note channel. The note rides the existing channel, so the chart pixels stay byte-identical. A funnel with no sublists emits no note and is unchanged.

Data shape

Stage values must be monotonically non-increasing in authored order (top to bottom) — the taper and every printed conversion percentage assume each stage is a strict subset of the one before it.
The trailing value is a single number tolerant of thousands commas (4,800) — it takes the FIRST numeric run and discards everything after, so a magnitude suffix is silently dropped, not scaled: $12k parses as 12, not 12000. Use consistent full-magnitude numbers across every stage (12,000, not $12k) or the taper and every printed conversion percentage will be wrong.

Anatomy

┌─────────────────────────────────────────┐
│  header                                 │
│        Where the pipeline leaks.        │
│                                         │
│   Visitors    [============]   12,000   │
│     62%        [========]      4,800    │
│   Activated    [=====]         2,160    │
│     40%        [==]              864    │
│   Paid         [=]               670    │
│                                         │
│  footer                           1/19  │
└─────────────────────────────────────────┘

progressindependent metrics as labeled bars, not a narrowing pipeline
statsa row of headline figures with no drop-off relationship
piechartparts of a single whole rather than sequential stages
list-stepsthe stages are a process to walk through, not values to compare
big-numbera single conversion rate is the whole story