Two-Hour Rebuild of Karpathy's HackerTube: He Brought arXiv Papers into the Hacker News Comments
Karpathy used Claude to build a website in two hours that only recommends videos well-received in HN comments. A few days later, someone copied the idea and turned arXiv papers into a similarly styled curated collection. More than 1,000 papers, no algorithmic recommendations, no login, all filtered by HN discussion popularity. It looks beautiful, but the person maintaining it has already started to hesitate about whether to shut it down.
Karpathy spent two hours on a weekend building HackerTube, a site that only collects YouTube videos repeatedly recommended in Hacker News comments. There is no algorithm, no watch history, and thumbnails are captured directly from the frame at 50% of each video. He tweeted that the experience was “significantly better.”
A few days later, someone used the same approach to make an arXiv paper version: Hacker Papers.
Elvis said in a tweet that he liked Karpathy's HackerTube idea, so using a similar prompt and data source, he had an agent build the arXiv version. It includes more than 1,000 papers, categorized by dimensions such as HN discussion popularity, hidden gems, and recent mentions. No account is needed; you can open it and search.
Karpathy's original HackerTube looks like this:
Elvis revealed in a reply that this project also took about two hours. The technical approach was similar: use Claude Code, use an API key to fetch YouTube metadata, spin up a VPS, and let the agent handle deployment and optimization. He specifically noted that no account is needed to access it; it is simply a collection to help discover interesting papers.
Someone in the comments asked: arXiv doesn't have comment signals like HN, so how is it ranked? Elvis replied that it was a combination of multiple signals but did not elaborate. “If people really like it, I'll spend time cleaning it up and organizing it.”
A commenter pointed out that building it in two hours isn't the problem; maintenance is. Elvis himself admitted that he isn't sure whether he'll keep it long term, because maintenance is a bit challenging. This is probably the common fate of all weekend hack projects: quick to build, hard to keep alive.
Another detail mentioned was that Karpathy filtered 43M HN comments, first using Claude for regex and spam filtering, then handing the rest to Sonnet. Someone joked that after reading so many “well, actually”-style comments, the agent probably already has PTSD.
Karpathy later replied that in the comment sections of recommended videos, the recommenders are often friendly and helpful. That's an interesting finding: when it comes to recommendations, HN's discussion atmosphere is unexpectedly positive.
The video version is more vivid; someone directly posted a GIF of themselves typing at a computer:
Elvis also mentioned that this project reminded him of the days when he worked on Papers with Code. “We were obsessed with finding paper gems through various signals, but the most important signal is actually whether people are talking about the paper at all.”
So, if you want to build one yourself too, the prompt Karpathy gave is simple: “Hi Claude good morning how are you I'm great thx build me a YouTube-style site but restricted to videos that have been repeatedly recommended on HN over the years pls. Don't make any mistakes.”
A commenter said that “don't make any mistakes” is a load-bearing wall. Give it a try—two hours later you too can have your own version. Just don't forget that maintaining it may require another two hours.
发布时间: 2026-11-03 00:41