HN.watch creates explainer videos for Hacker News posts on demand.

Scrimba founder Per launched HN.watch, a service that uses an LLM to generate HTML-based explainer videos for Hacker News posts the first time a user opens a link, at a cost of approximately $0.04 per video and roughly 4 seconds from click to playback. Scrimba Explain, available via web UI, MCP, a ChatGPT plugin, and a Chrome extension, is built on the Imba language, the OP sync engine, and the Q agent context management system, and uses Gemini, GPTs, Inworld, and ElevenLabs models. Per is seeking feedback and additional use cases, expecting pushback from Hacker News's text-favoring community.

HN.watch creates explainer videos for Hacker News posts on demand. Per, founder of Scrimba YC S20 , says Scrimba Explain uses an LLM to create HTML-based explainer videos. HN.watch generates one the first time someone opens a Hacker News link. His hypothesis is that if video creation moves from “dollars and minutes” to “cents and seconds,” new use cases will unlock for people who prefer video to text. What is Scrimba Explain? Scrimba spent the last decade teaching people how to code with an HTML-based video format. The team has now plugged an LLM into it so people can create explainer videos about anything. HN.watch demonstrates the technology by replacing Hacker News articles with explainer videos generated on the fly. Why does Scrimba use HTML-based video? Although HTML has obvious visual drawbacks compared with diffusion models, Scrimba identifies three major benefits: - Speed: Much faster than pixel-based videos, taking just a few seconds from click to playback. - Cost: Approximately $0.04 per video , excluding image generation, which some videos utilize and can quickly blow up the cost. - Easy editing: These benefits also make AI-assisted editing cheap & fast. What new use cases does Per see? Scrimba has already identified several possibilities: - A video explanation of every single Pull Request, as Scrimba does internally - A video for every page in internal or external documentation - Turning a complex article into a video in ~4 seconds through its Chrome extension - Helping course creators quickly draft lessons before recording the real thing - Creating personal stories for children, wedding invitations, birthdays, and more How does the custom stack work with LLMs? The stack is based on Imba , an open-source programming language created by Scrimba CTO Sindre Aarsæther . It compiles to JavaScript and interoperates fully with the npm + node ecosystem. Scrimba also built its own sync engine, OP , and an agent context management system, Q . The team expected LLMs to struggle because these technologies were not well represented in training data, but LLMs have performed surprisingly well. The stack is extremely dense and compact. In OP, a single declaration sets storage, sync, permissions, UI, and what the AI sees. This removes translations between frontend, API, db, and JSON that could confuse models and lead to errors. Instead of using React.js, Express, Supabase, and LangChain https://promptcube3.com/en/tags/langchain/ , Scrimba built everything from scratch—admitting that it is suffering from the “not invented here” syndrome, lol. Which models power Scrimba Explain? Scrimba uses Gemini https://promptcube3.com/en/tags/gemini/ , GPTs, Inworld, ElevenLabs , and a few others. What can people try? People can access Scrimba Explain through: - The Web UI: https://scrimba.com/explain - MCP https://promptcube3.com/en/tags/mcp/ , which can be added to a coding agent - ChatGPT https://promptcube3.com/en/tags/chatgpt/ Plugin - Chrome Extension A real pixel-based video demonstration is available on YouTube: https://www.youtube.com/watch?v=k6rbHmBxSEs More about Imba is available at: https://imba.io/ What feedback is Per looking for? Per is interested in feedback and ideas for other use cases. He expects pushback from Hacker News because its community strongly favors text, and acknowledges that the tool is not for everyone. He also notes that many people prefer videos to text today, especially younger generations. Next PaperMono e-ink magnet syncs shopping lists via phone web app → https://promptcube3.com/en/threads/9657/ All Replies （0） Want a live back-and-forth? Join the global AI chat room https://promptcube3.com/en/chat/ — login to talk. No replies yet — be the first