PowerPoint export (--format pptx)

slidelang build deck.slidelang --format pptx produces an editable .pptx.

slidelang build deck.slidelang --format pptx --output ./dist

The defining property of this format is that it never launches a browser. Every other rich output path can fall back to headless Chromium; PPTX has no such fallback by design, which is what makes it the format that works on a machine with no Chromium installed at all. That single constraint explains most of what follows.

What lands in the deck

Each content block becomes one slide. Titles and subtitles use the layout’s own placeholders; body content is stacked vertically as freeform shapes.

Element	Rendered as
Text	Text box, with inline bold/italic/code and the [x]{.token} spans resolved per segment (tokens from v2.32.4; see Inline Formatting for which of the fourteen carry formatting)
Bullet lists	Bulleted paragraphs, one level of nesting
Tables	Native PowerPoint table, including merged cells
Images	Embedded PNG/JPEG/GIF — local sources only
Quotes	Indented italic text box with an attribution line
Checklists	Bulleted list using ☑ / ☐ as the bullet character
Code	Monospaced text box, no bullet, markdown left literal
Charts	Rasterized PNG — see below

Everything is a real shape, so the result stays editable in PowerPoint: you can move things, retype text, and restyle. Because the generator has no font metrics available, vertical stacking uses an estimate — if a block wraps differently than predicted, the spacing is approximate, not the content.

Checklist state lives in the bullet

A checked item gets ☑ and an unchecked one ☐, as the paragraph’s bullet character rather than as text prepended to the content. That means the state survives the reader rewriting the item’s text in PowerPoint.

Code blocks are not parsed as markdown

Inside a code block, * and ` are literal characters. They are deliberately excluded from the inline-markdown pass that text and bullets go through, so a snippet containing a := *ptr survives verbatim.

Charts

Charts are rasterized to PNG by a pure-Go renderer — no browser, no network.

Native chart types: bar, line, pie, doughnut. A type without a native mapping (radar, combo) is skipped with a warning and replaced by a visible [Chart not rendered: <type>] marker, rather than silently vanishing.

Charts with an options: block are drawn approximately

Chart.js configuration has no equivalent in the native renderer. Rather than omit such charts — which in practice would mean omitting almost all of them, since real charts nearly always carry options: — they are drawn with what the native renderer does support, and the build logs exactly which keys were not applied:

⚠️  PPTX: el chart "bar" se dibujó de forma aproximada — de options: plugins,
    responsive, scales el renderer nativo solo aplica el título

The chart title is recovered from options.plugins.title.text, since that is where Chart.js expects it and where these decks normally put it. A display: false on that title is respected, and a top-level title: takes precedence.

Legends, series names, axes and categories are drawn from the chart’s data. What does not survive is the fine configuration: datalabel anchoring, legend position, axis titles, beginAtZero, plugin options.

Note

If you need a chart that honours its full Chart.js configuration, use --format html or --format pdf, where the rendering goes through a browser that applies it faithfully.

What is not exported

These are skipped with an explicit warning naming the element type — never silently:

Element	Why
Mermaid, PlantUML	Skipped by default, because --format pptx never starts Chromium. Pass --diagram-backend kroki and they are embedded: the build fetches a PNG from a Kroki server (--kroki-server points it elsewhere) and writes it into the deck as a picture. The skip warning names the flag. The only requirement is network access to that server
Maps	Leaflet tiles require a browser
Math	MathJax requires a browser
Special blocks, code groups, grids	Containers with their own layout, not a single shape
Remote images (http://, https://)	Not downloaded; replaced by a text placeholder

Watch the build log rather than the deck — “a diagram is missing” should be a line you can read, not a mystery.

Local image confinement

Image sources come from document content, which is not trusted input. They are confined to --asset-root, defaulting to the input file’s own directory:

slidelang build deck.slidelang --format pptx --asset-root ./assets

An absolute path, or one escaping the root via .., is rejected and replaced by a [Image blocked: …] placeholder. Without this, a crafted document could embed an arbitrary local file from the machine running the build into the generated .pptx.

Comparison with the other formats

	pptx	html	pdf
Needs Chromium	Never	Only for offline-* render modes	Yes
Editable output	Yes	—	No
Mermaid / PlantUML	Only with --diagram-backend kroki	✓	✓
Charts	Approximate	Faithful	Faithful
Maps, math	✗	✓	✓

See Offline rendering & diagram backends for how to reduce or remove the Chromium dependency in the HTML and PDF paths.