This tool renders a ThothII HTML deck as one full-bleed PNG per slide and assembles those images into a 16:9 PowerPoint file with native speaker notes and document metadata. The HTML and notes JSON under presentations/ are the editable sources; the PPTX is a rendered release artifact.

Using images preserves the web typography and fine CSS details across machines. The tradeoff is that slide text is not editable in PowerPoint. Speaker notes remain native and editable.

Requirements

Node.js 18 or newer and npm.
Playwright's Chromium build.
Network access while rendering the current deck, because its Fraunces and Manrope fonts are loaded from Google Fonts. The render is therefore not fully hermetic.

Install the locked JavaScript dependencies and Chromium from the repository root:

npm ci --prefix tools/html-to-pptx
npx --prefix tools/html-to-pptx playwright install chromium

Dependencies are local to this tool. The scripts intentionally do not use globally installed npm packages.

Render slides

Use a dedicated render directory. The renderer removes stale files matching NN.png, writes fresh slide images, and creates a raw notes.json containing the title extracted from each slide.

npm --prefix tools/html-to-pptx run render -- \
  presentations/<deck>.html <render-dir> \
  --hide ".hud button,.hint"

The HTML deck must expose .slide elements activated by #N hash routes. Optional rendering flags are --scale, --width, and --height; their defaults are 2, 1600, and 900.

Build the PowerPoint file

Keep refined speaker notes in presentations/<deck>.notes.json, using the shape {"1": "...", "2": "..."}. Pass that file instead of the raw titles generated during rendering:

npm --prefix tools/html-to-pptx run build -- \
  <render-dir> presentations/<deck>.pptx \
  --notes presentations/<deck>.notes.json \
  --title "..." --author "..." --subject "..."

The output uses the wide PowerPoint layout (13.333 x 7.5 inches), with one image per slide. Edit the HTML and rebuild whenever slide content changes.

Validation

Run the syntax checks with:

npm --prefix tools/html-to-pptx test

Before publishing a regenerated deck, inspect at least one PNG at full resolution and use python-pptx to verify the slide count, the 12192000 x 6858000 EMU page size, and one picture per slide. python-pptx is an optional, currently unpinned QA dependency; it is not needed to render or build the deck.

The locked direct dependencies are Playwright 1.58.0 (Apache-2.0) and PptxGenJS 3.12.0 (MIT). Their transitive versions and integrity hashes are recorded in package-lock.json.

Temporary dependency exception

PptxGenJS 3.12.0 declares image-size 1.2.1, which npm flags for the availability-only GHSA-w3rx-r6r6-pgpr and GHSA-5p2g-fcmc-qvqq advisories. No patched image-size release exists as of 2026-08-31, and current PptxGenJS releases retain the dependency. The affected parser is not imported by PptxGenJS's published builder path used here; this tool also accepts only locally generated PNG slides with explicit dimensions. Do not use it with untrusted image inputs. Reassess this exception by 2026-11-29, or sooner when a patched dependency is released.