Companies

LMArena

lmarena.ai

Arena evaluates frontier AI models through community voting and real-world human feedback.

HQSan Francisco, California, United States
Employees51-200
Funding$250M
Valuation$1.7B
Revenue$30M ARR
20 active roles
Profile 8mo agoJobs checked 3d ago
Specialization
Not classified
Business
Model Evaluation
Market
Software Developmentand 1 more market values
  • Scientific Research
Ecosystem
Not classified
Customers
Enterprisesand 2 more customers values
  • Developers
  • Researchers
More details
Organization type
Commercial Company
Ecosystem
Not classified
Business
Model Evaluation
Specialization
Not classified
Market
Software Development, Scientific Research
Customers
Enterprises, Developers, Researchers
Delivery models
Hosted Software, Professional Services
Revenue models
Services Fees
Listing status
Not classified
Latest equity round
Series A
Reported funding amount
$200M-$1B

About

Arena, formerly LMArena, builds a community-powered AI evaluation platform and public leaderboards measuring model performance in real-world use. It serves enterprises, model labs, developers, builders, researchers, and creative professionals; its differentiation is grounding evaluations in large-scale human feedback and community voting.

Market

Arena competes in third-party AI model evaluation, benchmarking, and public leaderboard markets. Unlike primarily curated or static benchmark systems, it differentiates through large-scale real-world usage, anonymous human preference comparisons, transparent methodology, and continuously refreshed rankings across multiple modalities. It also monetizes this evaluation infrastructure through custom services for AI labs and enterprises.

Target Customers

Arena primarily serves AI model labs and enterprises evaluating models for software engineering, law, medicine, scientific research, and other production use cases. Its broader user base includes developers, AI researchers, entrepreneurs, small businesses, and knowledge workers who need real-world evidence about model quality.

At a Glance

Problem

LMArena addresses the difficulty of understanding how AI models perform in real-world use, rather than relying only on abstract or lab-based benchmarks. Builders, researchers, and creative professionals need a practical way to compare model responses, while AI labs and application developers need reliable evidence about strengths, weaknesses, tradeoffs, and overall system quality. The core use case is side-by-side comparison of frontier-model responses followed by human voting, which reveals which systems users actually prefer and generates feedback for improving models and applications.

The economic pain is the cost and risk of deploying models or AI applications without trustworthy evidence of how they will perform for real users. LMArena's public platform reduces information asymmetry through community feedback, while its commercial offering turns that feedback into a paid evaluation service for organizations making model and product decisions.

Product / Service

LMArena is a community-powered AI evaluation platform. Users interact with frontier models, compare their responses, and vote on the better answer; those judgments form a human-preference dataset and a public leaderboard. The leaderboard is intended to remain freely available, giving the broader market an accessible reference point for real-world model performance.

The company also sells AI Evaluations to enterprises, model labs, and developers. The service provides comprehensive evaluations grounded in community feedback, analytics on model strengths and weaknesses, auditable samples of the underlying feedback data, and service-level agreements with committed delivery timelines. Its stated benefits are more reliable model and application decisions while preserving a neutral methodology across commercial, open-source, public, and unreleased models.

Market

LMArena competes in AI evaluation, model benchmarking, and human-preference measurement. Its differentiation is the combination of large-scale community usage, real-world comparisons, a public leaderboard, and a commercial evaluation service. The supplied research does not identify specific named competitors, so the most defensible comparison is to other providers of model evaluation and benchmarking rather than to a particular company.

The company has substantial demonstrated traction rather than being pre-revenue. Tens of millions of builders, researchers, and creative professionals use the platform, and LMArena reports that it surpassed a $100 million annualized revenue run rate within eight months of launching its enterprise offering. It therefore appears to be monetizing an established public evaluation network through enterprise-grade evaluation services while continuing to operate the leaderboard as a public service.

Founders & Leadership

Anastasios AngelopoulosFounder
Co-founder & CEO
Wei-Lin ChiangFounder
Co-founder & CTO
Ion StoicaFounder
Co-founder & Chairman

Funding History

2025-05
Seed$100M

Andreessen Horowitz (a16z), UC Investments (University of California)

2026-01
Series A$150M

Felicis, UC Investments (University of California)

Recent News

2026-10-08funding
LMArena (Arena) raises $200M Series B at a $3.1B valuation

Arena, the company behind the LMArena leaderboard, announced a $200 million Series B at a $3.1 billion valuation. Lightspeed Venture Partners and Khosla Ventures led the round; Salesforce Ventures, 01 Advisors, Dell Technologies Capital, Endeavor Catalyst, a16z, and Felicis also participated.

2026-10-08product_launch
Arena launches its AI Alignment Index

Arena announced the launch of its AI Alignment Index alongside its Series B announcement. The company described the index as a new tool to advance real-world AI evaluation.

2026-09-02partnership
LMArena/Arena opens Fall 2026 Academic Partnerships Program

Arena, formerly LMArena, opened the Fall 2026 cycle of its Academic Partnerships Program and invited proposals from tenure-track faculty at U.S. universities. The program provides funding and support for independent research advancing the scientific foundations of AI evaluation, with submissions due October 30, 2026.

2026-01-06funding
LMArena Raises $150 Million to Build the World's Most Trusted AI Evaluation Platform

LMArena announced a $150 million Series A led by Felicis and UC Investments. The announcement positioned the funding as support for building an AI evaluation platform and noted that its first commercial product launched in September 2025.

2025-12-18product_launch
Arena-Rank: Open Sourcing the Leaderboard Methodology

Arena open-sourced Arena-Rank, a Python package for the ranking methodology that powers the LMArena leaderboard. The release made the leaderboard’s ranking infrastructure more accessible for research and development.

2025-09-11other
Report: LMArena Business Breakdown & Founding Story

Contrary’s report described LMArena as a popular way to compare and evaluate AI models, citing more than 3 million comparisons and over 400 models evaluated as of April 2025.

Active Roles

20
OnSite - SF Bay Area/Operations/8d ago
OnSite - SF Bay Area/Engineering/9d ago
Hybrid - SF Bay Area; Remote, New York/Marketing/12d ago
Hybrid - SF Bay Area; Remote, New York/Marketing/16d ago
OnSite - SF Bay Area/Product/23d ago
OnSite - SF Bay Area/Engineering/24d ago
OnSite - SF Bay Area/HR & Recruiting/24d ago
OnSite - SF Bay Area/Design/31d ago
OnSite - SF Bay Area/Engineering/32d ago
OnSite - SF Bay Area/Technical Account Manager/38d ago
OnSite - SF Bay Area/Engineering/52d ago
OnSite - SF Bay Area/Operations/66d ago
Technical Recruiter$150k – $260k
OnSite - SF Bay Area/HR & Recruiting/79d ago
OnSite - SF Bay Area/Engineering/79d ago
OnSite - SF Bay Area/Data & Analytics/79d ago
OnSite - SF Bay Area/Solutions Engineer/79d ago
OnSite - SF Bay Area/Data & Analytics/79d ago
OnSite - SF Bay Area/Engineering/79d ago
OnSite - SF Bay Area/Legal/79d ago

Business Model

Public voting and leaderboards are free, while Arena sells paid private and comprehensive AI evaluation services to businesses, enterprises, model labs, and developers. The evaluation business is the company's primary commercial revenue stream.

Products

Arena public model leaderboards and Battle Mode for text, image, code, video, and agent modelsAI Evaluations, a paid evaluation-services offering for enterprises, model labs, and developersCode Arena, a full-stack environment for building, deploying, and evaluating AI-generated applicationsArena Expert and Occupational leaderboards for expert-level reasoning and domain-specific model performanceOpen research datasets and evaluation methodology built from Arena interactions

Customers

OpenAIGoogle DeepMindAnthropicMeta

Tech Stack

Large language and multimodal AI models, including text, image, code, video, and agent modelsCrowdsourced human-feedback and anonymous pairwise-comparison evaluationBradley-Terry statistical ranking, with contextual and style-control extensionsAnonymized conversation, prompt, vote, and model-pairing datasetsAutomatic prompt tagging and continuously updated leaderboard analytics

Competitors

Artificial Analysis
Scale AI SEAL Leaderboards
Hugging Face Open LLM Leaderboard
Stanford HELM
LayerLens

Key Investors

Felicis, UC Investments, Andreessen Horowitz, The House Fund, LDVP, Kleiner Perkins, Lightspeed Venture Partners, Laude Ventures