Track slides in a custom HTML deck

Lumdeck measures reading per slide when it can detect the current slide. Recognised deck frameworks and supported hash navigation provide that signal automatically; a custom deck can report its position through Lumdeck's deck protocol.

What the protocol does

The deck reports readiness and slide changes to the surrounding viewer. The viewer validates messages and associates the position with the current presentation. It is not a channel for account data, viewer identities or arbitrary network access.

The public developer overview explains the capability. Detailed integration code and configuration remain in the premium developer panels. Use the supplied protocol examples there rather than guessing event names or message payloads.

Verification checklist

1. Upload a small deck with at least three clearly numbered slides.
2. Open its normal viewer and move forward, backward and directly to a slide.
3. Confirm the surrounding slide indicator follows the deck.
4. Create a disposable share link and view multiple slides with different dwell times.
5. Check the link's analytics after processing. Respect Do Not Track and the published counting rules when interpreting a missing view.

Frameworks and limits

reveal.js is automatically detected. Supported hash navigation is also followed. Verify your particular Slidev or Marp export before relying on per-slide totals: themes, plugins and custom navigation can change how positions are exposed. A chart click or animation step is not necessarily a new slide.

Deck analytics describe visits and reading, not a guarantee that someone understood or watched every element. Read how analytics work, and use a normal share link when testing audience behavior.

Last updated: 7 October 2026. See current plans and product scope and limits.