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Anastasios Angelopoulos
Co-Founder & CEO, Arena

LMArena Co-Founders on the Future of AI Rankings

📅 Jun 05, 2025 Bloomberg Live 11 MIN 5036 VIEWS 24 SEGMENTS · 3 SPEAKERS
Anastasios Angelopoulos and Wei-Lin Chiang, Co-Founders of LMArena, a leaderboard ranking the best LLM and AI chatbots through community voting speak about the evolution of their company with Bloomberg’s Rachel Metz at Bloomberg Tech in San Francisco. -------- Subscribe to Bloomberg Live on YouTube:    / @bloomberg_live  

Questions asked in this interview

8
  1. 0:00Explain what else LMArena is and what is it exactly that you guys are measuring over there?
  2. 1:28What do you think we'll learn?
  3. 3:01What is the use, though, of these so-called benchmarks?
  4. 4:39How is that money going to help you grow LMArena from a research project into an enduring company?
  5. 5:54I'm just curious how important it is to you to make the user base more diverse, and how are you going to do that?
  6. 8:02How much do you think that information matters?
  7. 9:44... report alleging issues such as that some companies can game LMArena by submitting private models, or sorry, many models for private testing and then only publishing scores for the ones that perform best. Can companies game LMArena?
  8. 10:45How do you envision turning LMArena into a successful business but also remaining a neutral testing platform?
Interviewer 0:00 ↗
Explain what else LMArena is and what is it exactly that you guys are measuring over there?
Anastasios Angelopoulos 0:03 ↗
Sure. So LMArena is an open community platform for testing and evaluating all the top AI models. So you can go to lmarena.ai, and what you'll see is the ability to interact with not just ChatGPT, but also Google's Gemini or Anthropic's Claude, and not just interact with them, but also to battle them against one another. So you can chat and then you'll see two anonymous models and say, compare which one is better, vote for it. And we use those votes to construct a leaderboard of which models are best on the distribution of real-world use, also on different tasks like math, coding, instruction following. And it's not just us using this, but we have a community of millions of people that come to the platform and vote. They come for all sorts of reasons. It's pretty diverse: 60% tech, but 40% all sorts of other things, just to try different things and to use them all in one platform. So that's what LMArena is. And if you have anything to add, Wei-Lin.
Wei-Lin Chiang 0:59 ↗
Yeah, and today we are excited to be here, and we actually built a custom LMArena just for Bloomberg, so people can check it out on Bloomberg. You can go there and then ask questions. We did a text-to-image arena this time, so you can input whatever description you want to generate an image, and then compare the image models. And we have a live leaderboard. It'll be cool to see what the Bloomberg audience likes best.
Interviewer 1:28 ↗
So this started as an academic research project. At the time, you two were both graduate students at UC Berkeley, and it's really caught on over the last couple of years. Companies like OpenAI, Google, Anthropic, they use it to test out different AI models, sometimes in advance of them being released. What do you think has struck a chord with companies and also with the people who are coming to try out these models? What do you think we'll learn?
Wei-Lin Chiang 1:59 ↗
So yes, we've been running this project since two years ago. And then these days we've been working with all the frontier AI labs, including OpenAI, Google, actually, Meta, to test their pre-release models. And because these days it's been becoming a technical challenge right now to how to evaluate these AIs, especially for real-world use cases. So we've been focusing on scaling this platform in order to capture, you know, a very diverse user base covering all different industries.
Anastasios Angelopoulos 2:35 ↗
So yeah, maybe it's also worth saying, you know, part of the reason why people come is they like seeing multiple opinions. They like seeing multiple AIs in one place and using them all in one interface and comparing them, being able to do so on one platform. And they're also really excited by the opportunity to look at some new models from the top providers pre-release. So they all sort of appreciate that, and that's what's led to some growth.
Interviewer 3:01 ↗
What you guys are doing is one of many different kinds of attempts to measure capabilities of new models, especially of powerful AI models that are sometimes called frontier models. What is the use, though, of these so-called benchmarks?
Anastasios Angelopoulos 3:17 ↗
Sure. So I think it's worth maybe zooming out and thinking a little bit about what is a standard benchmark in AI versus what is LMArena. So in a standard benchmark, what happens is you are looking at a narrow vertical of tasks. Think about something like an ImageNet or an MMLU, which is a multiple-choice question-answering dataset. Let's say multiple-choice question answering. I want to understand how good my models are, so I'm going to collect a bunch of multiple-choice questions. I'm going to have experts label them. I'm going to collect that into a dataset. I release it online or I keep it private. And then I have models answer those questions and then I see how they perform. So that's the standard paradigm of so-called benchmarking. Now, what's the issue with this? The issue with this is in the current era of AI, things are moving so quickly and AI models are doing all these subjective tasks that are so broad that you really could never collect a single dataset or even 10 or 20 datasets that would parameterize all the possible real use cases. We work a little bit differently, though, in the sense that we have this community of millions of people that come to the website and they're asking basically whatever they want. And so it encompasses a huge diversity of tasks that we then collect human preference about. So we ask them which ones they like better and then use that massive data to extract analytics. So we're basically inverting the problem from, hey, I'm going to look at this particular narrow task, and instead saying, let's take all the data we have and extract analytics from that in terms of which models are best.
Interviewer 4:39 ↗
Okay. And so as I said before, this started as a research project. You have turned it into a company very recently, and you just closed a large funding round for your company, 100 million, which values the company at 600 million. How is that money going to help you grow LMArena from a research project into an enduring company?
Anastasios Angelopoulos 4:57 ↗
So we haven't commented at all on the valuation, first of all. But in terms of where we're going to put the money, the platform is actually quite expensive to run, and the reason is because we have a lot of users that are coming in using the AIs, and we're hoping to scale the community. I think Wei-Lin should talk more about that. But as the community scales, our costs of running it are also going to scale. So we're just planning for success here in terms of growing the platform and serving our user base.
Wei-Lin Chiang 5:26 ↗
So right now we are serving over a million monthly users right now. And then with the new product launch just last week, we are basically transitioning to a more user-friendly UI/UX in order to scale the usage of it. So you can imagine operating as a platform to serve tens of millions of users.
Interviewer 5:54 ↗
So right now, as you mentioned, the majority of people that are testing our models on LMArena come from the tech community. The rest come from all various types of people. I'm just curious how important it is to you to make the user base more diverse, and how are you going to do that?

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Cite this transcript

APA, MLA, BibTeX
APA

Angelopoulos, A. (2025, June 5). LMArena Co-Founders on the Future of AI Rankings [Interview transcript]. Bloomberg Live. CEOInterviews.AI. https://ceointerviews.ai/interview/3026879/

MLA

Anastasios Angelopoulos. "LMArena Co-Founders on the Future of AI Rankings." Bloomberg Live, 5 Jun. 2025. Transcript, CEOInterviews.AI, https://ceointerviews.ai/interview/3026879/.

BibTeX
@misc{angelopoulos2025_3026879,
  author       = {Anastasios Angelopoulos},
  title        = {LMArena Co-Founders on the Future of AI Rankings},
  howpublished = {Interview transcript, Bloomberg Live. CEOInterviews.AI},
  year         = {2025},
  month        = {jun},
  url          = {https://ceointerviews.ai/interview/3026879/},
  note         = {Speaker-attributed transcript with timestamps}
}