pdf-presenter

Lightweight CLI that serves a PDF as browser slides with a full presenter mode — speaker notes, next-slide preview, pause-able timer, audio recording with per-slide timeline metadata, and resizable panes. No markdown conversion, no native dependencies. Point it at a PDF and go.

繁體中文版 →

npx pdf-presenter slides.pdf           # serve & open browser
npx pdf-presenter -gn slides.pdf       # generate a notes template
npx pdf-presenter slides.pdf -t 20     # 20-minute countdown
npx pdf-presenter ./slides/            # browse a directory of PDFs

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Why

Presenting a PDF deck usually means either:

• Opening the PDF in a viewer and losing speaker notes / next-slide preview, or
• Converting slides to HTML (and fighting layout, fonts, and build tooling).

pdf-presenter takes a third path: keep the PDF as-is, render it with pdf.js in the browser, and layer a presenter window (current + next + notes + timer) on top. Slide state syncs between the audience and presenter windows via BroadcastChannel — no WebSocket, no server round-trip.

Features

• Zero config. One argument: the PDF file.
• Dual views. Audience view (fullscreen slide) and presenter view (current, next, notes, timer, counter).
• Speaker notes from a simple JSON file. Generate a template from the PDF text with -gn, or edit notes directly in the presenter view — changes are saved back to slides.notes.json automatically (debounced).
• Timer. Count up by default, or count down with --timer <minutes>. Colour shifts yellow in the last 5 min, red in the last 1 min.
• Keyboard-first. Arrow keys, Space, PageUp/Down, Home/End, plus F freeze, B black, R reset timer.
• Multi-window sync via BroadcastChannel — the presenter window drives one or more audience windows in the same browser.
• No native deps. Pure JavaScript. pdf.js does the heavy lifting.

Install

Run without installing:

npx pdf-presenter slides.pdf

Or install globally:

npm i -g pdf-presenter
pdf-presenter slides.pdf

Requires Node.js ≥ 18.

Usage

Serve a PDF

pdf-presenter <file.pdf> [options]

Flag	Alias	Default	Description
--port <n>	-p	3000 (auto-increments if taken)	Server port
--no-open			Don't auto-open the browser
--presenter		false	Open directly in presenter mode
--notes <path>	-n	<file>.notes.json	Path to notes JSON
--timer <minutes>	-t	none	Countdown timer in minutes
--version	-v		Print version
--help	-h		Print help

On start you'll see:

🎯 pdf-presenter v1.0.0

   Audience:   http://localhost:3000
   Presenter:  http://localhost:3000/presenter

   PDF:   slides.pdf
   Notes: slides.notes.json (18/24 slides have notes)
   Timer: 20:00

   Press Ctrl+C to stop.

Share the audience URL (or window) with your viewers. Keep the presenter URL for yourself.

Generate a notes template

pdf-presenter -gn slides.pdf
pdf-presenter --generate-presenter-note-template slides.pdf
pdf-presenter -gn slides.pdf --force    # overwrite existing

This reads the PDF, extracts the first line of text from each page as a hint, and writes slides.notes.json next to the PDF:

{
  "meta": {
    "pdf": "slides.pdf",
    "totalSlides": 24,
    "generatedAt": "2026-04-10T12:00:00.000Z",
    "generator": "pdf-presenter"
  },
  "notes": {
    "1": { "hint": "Introduction — Welcome", "note": "" },
    "2": { "hint": "Agenda — Topics for Today", "note": "" }
  }
}

• hint is auto-extracted and shown in the presenter view when a slide has no note.
• note is what you write. It appears as the speaker notes in the presenter view.
• Keys are 1-indexed slide numbers.

If slides.notes.json already exists, -gn aborts with a warning — use --force to overwrite.

Editing notes live

The presenter view doubles as an editor: click into the notes panel and type. Changes are saved back to slides.notes.json automatically (debounced ~600 ms after you stop typing). A small status indicator shows Saving… / Saved / Save failed next to the panel title.

• While the notes textarea is focused, keyboard shortcuts (arrow keys, F, B, R) are disabled so typing isn't hijacked. Press Esc to blur the editor and return to slide navigation.
• If slides.notes.json doesn't exist yet, the first save creates it.
• Existing hint fields are preserved. The panel title shows the hint for the current slide in a muted style.
• Writes are serialized server-side, so edits from multiple windows can't clobber each other mid-write.

Keyboard shortcuts

Both views:

Key	Action
→ / Space / PageDown	Next slide
← / PageUp	Previous slide
Home / End	First / last slide (presenter)

Audience view only:

Key	Action
P	Open presenter view in a new window

Presenter view only:

Key	Action
F	Freeze / unfreeze the audience view
B	Black out the audience view
R	Reset the timer

Typical workflow

# 1. Generate the notes template
pdf-presenter -gn slides.pdf

# 2. Edit slides.notes.json in your editor, fill in "note" fields

# 3. Present
pdf-presenter slides.pdf --timer 20

Then:

1. The audience URL opens in your browser — share that window (or drag it to your projector / second display).
2. Open the presenter URL in a second window on your laptop screen.
3. Drive the deck from the presenter window. The audience window follows automatically.

How it works

• pdfjs-dist (Mozilla pdf.js) renders each page to a <canvas> in the browser, scaled to fit the viewport at device-pixel-ratio resolution.
• The Node CLI ships a minimal http server (no Express, no middleware) that serves:
  • / → audience HTML
  • /presenter → presenter HTML
  • /slides.pdf → your PDF, streamed from disk
  • /notes.json → the notes file (or an empty stub if missing)
  • /assets/* → UI JS/CSS
  • /assets/pdfjs/* → the pdfjs-dist library and worker
• The presenter window broadcasts slide changes via BroadcastChannel("pdf-presenter"). Audience windows in the same browser listen and re-render.
• Notes text extraction for -gn uses the legacy pdfjs-dist build, which runs in Node without a DOM or canvas.

Development

make install    # pnpm install
make build      # tsup build → dist/
make check      # tsc --noEmit
make run        # build + run against test/fixtures/sample.pdf
make clean      # remove dist/ and node_modules/

Project layout:

pdf-presenter/
├── bin/pdf-presenter.ts       # CLI entry point
├── src/
│   ├── cli.ts                 # commander setup, command dispatch
│   ├── server.ts              # HTTP server + route map
│   ├── generate-notes.ts      # -gn command
│   ├── utils.ts               # path/port helpers
│   └── ui/                    # static frontend
│       ├── audience.html
│       ├── presenter.html
│       ├── presenter.css
│       └── presenter.js       # pdf.js rendering + BroadcastChannel sync
└── test/fixtures/             # sample PDF for smoke tests

License

MIT