“A Festival of Writers Who Are Wrong on the Internet”
June 5 – 7, 2026 · Berkeley, CA
LessOnline is a festival celebrating truthseeking and blogging. It’s an opportunity to meet people you’ve only ever known by their LessWrong username or Substack handle.
The goal is to bring together a “mostly-online subculture of people trying to work together to figure out how to distinguish truth from falsehood using insights from probability theory, cognitive science, and AI.”
The weekend will be filled with talks, workshops, dance parties, and late-night conversations around the fireside.
This is the third year of LessOnline. Last year over 700 people attended, and we’re expecting roughly the same number this year.
The sites below embody the virtues we are celebrating. Each author below has been offered a free ticket
LessOnline 2025








What attendees had to say
Fig. I — Like Moths to a Lightbulb
For Jorge Luis Borges, paradise was a library. At nearly 70 years of age, I’ve found my paradise at Lighthaven… I know of nowhere else on Earth where I can find so many interesting conversations in such a compact area.

What I’ll remember most from LessOnline is not the sessions, mine or others’, but the unending conversation among hundreds of people all over the grounds, which took place in parallel with the sessions and before and after them, from morning till night. It felt like a single conversational archipelago, the largest in which I’ve ever taken part, and the conference’s real point.

I had a great time at LessOnline. It was both a working trip and also a trip to an alternate universe, a road not taken, a vision of a different life where you get up and start the day in dialogue with Agnes Callard and Aristotle and in a strange combination of relaxed and frantically go from conversation to conversation on various topics, every hour passing doors of missed opportunity, gone forever.
Secure your place at the festival
Fig. II — The Printing PressFull access to LessOnline, Summer Camp, and Manifest. All meals included.
Three days of conversation, talks, debates, unconferences, and late-night arguments. 5 meals included.
A week on campus between LessOnline and Manifest. Workshops, classes, projects in a relaxed environment. Meals included.
A festival for prediction markets, forecasting, and spirited debates about the future. Friday evening through Sunday. 5 meals included.
Questions & answers