Karpathy Built HackerTube, a Catalog of 6,454 Videos, in Two Hours with Claude Code

Andrej Karpathy built HackerTube in two hours, an alternative interface for watching videos that already live on YouTube. It is not a new video platform, and it does not compete on scale: at launch the catalog holds 6,454 unique videos sorted into 150 topics. They were selected from an archive of 43 million Hacker News comments, spanning 2007–2026, from a community of programmers and technical specialists. Claude Code ran the development. According to Karpathy, he wrote no code himself.

Where the 6,454 videos came from

The trigger was irritation with YouTube's recommendations: repetitive content and clickbait thumbnails. Karpathy decided to build a video library based on what Hacker News users mention.

The source was an archive of 43 million comments from 2007–2026. The system first filtered for comments containing YouTube links. Claude Sonnet then went through the remaining mentions and removed spam. The result was about 40 thousand mentions, which boil down to 6,454 unique videos across 150 topics.

There is an important caveat. A video being mentioned many times in comments does not mean it was praised each time: someone may have linked to it to argue with it or criticize it. So HackerTube reflects popularity among Hacker News participants, not confirmed quality.

What the service does and where the videos are hosted

Karpathy did not download the videos and does not store them. The player works through YouTube, while HackerTube provides the catalog, search, recommendations and the viewing interface. Users can search by topic, get personalized picks, save videos they like and keep a watch history. No registration is required: user preferences are stored in the browser.

Instead of the creators' own thumbnails, the site shows a frame from the middle of each video. That way the preview stops being an ad for the video and shows what it actually contains.

How two hours turned into a working service

According to Karpathy's description, Claude Code ran the development on a model he calls Opus 5.5. Claude Sonnet was brought in for bulk processing of the comments. He says he wrote no code himself and only explained to Claude what needed to be done.

Three actions had to be done by hand:

• create a Google API key to retrieve YouTube metadata;
• rent a virtual server (VPS);
• buy a domain name.

Karpathy then gave Claude the server's IP address and told it to install, configure, secure and deploy the application. By his account, the agent handled this on its own. This cannot be independently confirmed: the account rests on the author's description of the project in his blog and on the site itself. All that is known about the security of the deployment is that the agent was tasked with it; there has been no external audit.

What this project actually shows

The news is not that yet another YouTube interface with six thousand videos has appeared. What stands out is the chain of steps: one person, in a couple of hours, organized the processing of an archive of tens of millions of comments, built a web service and put it on the internet. The author of the Telegram post cautions that to get this result you "have to be Karpathy": you need to understand in advance what architecture to ask for and how to check the outcome.

For working developers, the takeaway is practical. The routine work around a small service — parsing data, filtering spam with a language model, configuring a server, deploying — can already be delegated to an agent. What remains for the human is defining the task, obtaining keys, paying for infrastructure and evaluating the result. At the same time, the dataset (Hacker News comments) and the classifier model determine the quality of the catalog more than the speed of the build does.

The Telegram post's author also speculates that the project could be shut down: by his account, Anthropic now prohibits copying apps and games. That is his opinion, not a confirmed fact.

The site is available at hackertube.org, and Karpathy published a detailed description of the project on his blog.