Open-source document analytics for HTML.
HTMLRadar tells you who read your HTML, and which sections they actually dwelled on. Upload a file or paste a URL. Send the tracked link. Watch the read happen in real time.
No card needed. Open source under AGPL-3.0.
02 · The shift
For two decades, the documents that mattered ended in .pdf. Investor decks, briefs, board updates, research reports. Now they end in .html. The piece nobody built was the one that tells you what happened after the link went out.
03 · The moment
Marc just opened Seed Deck, Q2.
Lightspeed · 2m 41s on §03 The Ask · still active
Marc at Lightspeed opened it three times. Spent 6m 14s. Read the Ask, Team, and Traction sections. Skipped Market sizing.
04 · What it does
One document, many shares. Each share carries its own email gate, password, expiry, and revocation. The dashboard tells you which one Marc opened, not "someone opened it."
Re-upload after partner feedback. Every share you've already sent now points at v2. No re-sending. No broken URLs in inboxes.
A three-second dwell threshold separates a real read from a scroll-past. Most analytics count both. HTMLRadar doesn't.
05 · The loop
Three frames. The sender's notification fires. The recipient lands at the email gate. The document renders. Each frame is real product output, not a slide.
Marc opens the tracked share from his inbox. Three seconds later the sender's notification fires.
Marc just opened Seed Deck, Q2.
Lightspeed · 2m 41s on §03 The Ask · still active
A lightweight gate captures the recipient's email before the document renders. Optional password or domain allow-list per share.
The original HTML, untouched. Section dwell tracked from this point on. The sender's dashboard fills with reads in real time.
06 · Open source
The tracker, the proxy worker, the schema, the web app — all of it lives on GitHub. The hosted version at htmlradar.com is for people who'd rather not run their own Cloudflare and Supabase. Both options run the same code.
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