Karpathy builds HackerTube from 6,454 videos in two hours

Andrej Karpathy published HackerTube, a YouTube-style site built from the videos Hacker News readers keep recommending to each other, and says Claude Opus 5.5 did nearly all of the work in about two hours.

Karpathy described the origin in a post on October 31: a tired Friday night on YouTube, looking at what he called an "enshittified wall of slop." By Saturday morning he had handed Opus 5.5 the job. "Let's write our own YouTube clone based on whatever videos have been recommended on Hacker News," he wrote. Opus came back with hackertube.org.

What is HackerTube?

The site lists 6,454 videos posted to YouTube between 2007 and 2026, sorted into 150 topics. They come from 39,834 Hacker News comments that recommend a YouTube video, pulled from the full public HN archive. Per Karpathy's account, Claude downloaded every comment, filtered it, then ran Sonnet over the pile in a Claude Code Workflow to strip spam and low-grade posts, leaving about 40,000 recommending comments.

The cut is stricter than a single link. HackerTube's About page says a video is kept only if at least three different people linked it with real commentary, in at least three different months, which left roughly 7,000 videos before a final cleanup. The site credits its comment labels, video cards and topic list to teams of Claude Sonnet 5.5 agents that Opus 5.5 coordinated, and the videos play through YouTube's privacy-enhanced embed.

Karpathy said the build "takes ~2 hours now," working in the Claude Code desktop app for Mac with Opus 5.5 on medium effort, and he wrote that he no longer does what he called traditional engineering. He put the token bill in a Hacker News reply: "504M input tokens (90% cached), 7.6M output tokens." Most of that was Sonnet calls labeling the comments, with about 1M Opus 5.5 tokens for the app and deploy. The three jobs he did by hand were creating a Google Cloud API key for YouTube metadata, booting a VPS, and buying the domain.

The post drew more than 2,600 points on Hacker News, as read on November 2, 2026, and commenters adapted it fast: one built a books version, another a small Apple TV app, a third a feed for a game-development community. Karpathy answered requests in the thread and pushed the results, adding filters for duration and video type, a "recently recommended" sort, and "HackerTube Longs," every video over an hour placed where YouTube shows Shorts.

The caveats are real. No dollar cost has been published; Karpathy wrote that he is on a subscription, and explainx.ai notes the spend is undisclosed. Nothing measures how accurate the filter is or how many good recommendations it dropped. The underlying Hacker News archive was last updated August 23, 2026, so recommendations from this fall are missing. The taste on the site is Hacker News' own, and a model labeled every comment with no human review. One commenter said the list still includes sponsored and promotional tech videos. HackerTube runs on YouTube embeds, and Karpathy did not publish the server code, calling it "a vibe coded mess."

He did publish the data: a 17.8 MB zip with the video records, the 39,834 labeled comments, the taxonomy and the search vectors, under the ODC-By 1.0 license, plus a DATA.md written for AI agents to read.

HackerTube is live at hackertube.org; the data export sits on its about page.