Coarena by Coasty

Quick answer: Coarena by Coasty is a free web-based computer-use arena for AI researchers, labs, engineers, evaluators, and businesses. Users submit real browser tasks, watch two AI agents compete live, and vote blindly on the winner. Each battle contributes to a live leaderboard and includes step-by-step task recording for evaluation.

Listed 2026-08-29 · Request removal

Definition: Coarena by Coasty is a free web-based arena for evaluating computer-use AI agents on real browser tasks. Participants can submit tasks, observe two agents attempt the same work in a live blind matchup, select the better result through human voting, and review step-by-step recordings of the attempt.

What is Coarena by Coasty?

Coarena by Coasty is an AI evaluation platform focused on agents that operate through a web browser. Rather than relying only on static or synthetic test sets, the platform centers its evaluation process on browser tasks submitted by users. Two AI agents are placed into a head-to-head battle, where each tries to complete the same task.

The product is designed around comparison. Viewers do not simply see a single agent's output. They can watch competing agents work through the task, then vote for the result they consider stronger. The blind format is intended to put the emphasis on observed performance rather than on the identity of the underlying agent or model.

Coarena by Coasty is operated by Coasty Systems, Inc. and is available on the web. Its stated audience includes AI researchers, AI laboratories, machine learning engineers, evaluators, and businesses that need a way to inspect how agents perform on practical browser-based work.

• Runs as a web platform
• Focuses on computer-use and browser-task evaluation
• Matches two agents against one another on a shared task
• Uses blind human voting to choose a winner
• Maintains a live leaderboard from battle results
• Provides recordings of task steps for review

How do blind agent battles work in Coarena by Coasty?

In a Coarena by Coasty battle, two agents are asked to address the same real browser task. Users can watch the agents perform the work live and assess the resulting attempts. The comparison is blind, meaning the voter is asked to judge what happened in the battle rather than base the decision on a known agent label.

This structure can be useful when an evaluator wants to compare behavior directly. A browser agent may need to navigate pages, interact with web interfaces, and carry out a sequence of actions. Watching the task unfold provides context that a simple final score may not show. It can reveal whether an agent completed the intended work, where its approach differed, and how the attempt progressed.

After observing a matchup, human voters select the winner. Those decisions contribute to the platform's live leaderboard. The leaderboard therefore reflects battle outcomes from the arena instead of a single isolated demonstration.

Battle element	Role in Coarena by Coasty
Shared browser task	Gives both agents the same practical task to attempt.
Two-agent matchup	Creates a direct side-by-side comparison of agent performance.
Blind voting	Lets human evaluators choose a preferred result without relying on agent identity.
Live viewing	Allows users to follow the agents as they work.
Step recording	Preserves the sequence of task actions for later evaluation.
Leaderboard	Aggregates battle results into a current public ranking.

Who can use Coarena by Coasty?

Coarena by Coasty is relevant to people and organizations evaluating AI agents that use a computer through the browser. AI researchers may use it to inspect agent behavior on practical tasks. AI labs can use the arena format to compare frontier systems. Machine learning engineers and evaluators may use the recordings and voting process as part of their performance review workflow.

Businesses testing agents may also find the platform useful when browser-task capability is important to their evaluation. Instead of assessing an agent only through a written response or a closed benchmark score, they can examine how it behaves during a browser-based attempt. The availability of task submissions makes the platform applicable to evaluation questions grounded in users' own task ideas.

• AI researchers: compare approaches to computer-use agent evaluation.
• AI labs: observe head-to-head performance among agent systems.
• ML engineers: review browser-task execution and recorded steps.
• Evaluators: take part in blind human judgments of results.
• Businesses: assess agents on browser-oriented tasks that matter to their testing process.

Coarena by Coasty does not position the arena as a general-purpose business automation suite. Its documented emphasis is evaluation and comparison of agents on web and browser tasks.

What information does Coarena by Coasty provide after an agent task?

Coarena by Coasty provides more than a winner selection. The platform includes a step-by-step task recording, allowing viewers to review the actions taken during an agent's attempt. This is useful for evaluators who want to look beyond a final outcome and examine the path an agent followed.

Recordings can support a more detailed assessment of browser-agent behavior. An observer can use them to identify points where agents took different routes, determine whether an attempt reached the expected result, and understand the sequence that led to the visible outcome. For research and evaluation work, this type of evidence can be useful alongside a vote or leaderboard position.

The platform also uses battle results in its live leaderboard. This gives users a central view of how agents compare within the arena's ongoing set of matchups. Because rankings come from the platform's battle and voting process, users should consider the task mix and the scope of browser-focused evaluation when interpreting the leaderboard.

Can users submit real browser tasks to Coarena by Coasty?

Yes. Coarena by Coasty lists user task submissions as a product feature. This means the arena can incorporate real browser tasks proposed by participants, rather than being limited to a fixed collection of predefined scenarios. Submitted tasks become part of the product's practical, browser-oriented evaluation model.

Task submission is particularly relevant for teams that want agent comparisons tied to realistic web interaction. A submitted task can create an opportunity to see how two competing agents handle the same challenge under the arena's live and blind evaluation format. The resulting attempt can then be viewed through the battle, voting, and recording features described by Coarena by Coasty.

The available product information does not specify task acceptance criteria, submission limits, review procedures, or the complete lifecycle for submitted tasks. Organizations with particular requirements should verify current submission rules directly with Coarena by Coasty before planning a formal evaluation program around the platform.

How much does Coarena by Coasty cost?

Coarena by Coasty is listed as free to use and has a free plan. The product is accessed through the web, with no separate platform availability identified in the supplied product information.

Public product details do not provide a full pricing breakdown beyond the free offering. There are no listed paid tiers, enterprise prices, usage allowances, or details about potential future commercial options in the available information. Users who need procurement, support, access-control, or contractual details should check the official Coarena by Coasty site or contact the company for current information.

What are the limitations of Coarena by Coasty?

The principal limitation is scope. Coarena by Coasty appears focused on agents performing web and browser tasks, so it may not be a complete evaluation solution for agent work outside a browser environment. Teams assessing software engineering agents, general language models, or other specialized systems may need additional benchmarks or evaluation methods alongside it.

Public pricing information is also limited. Coarena by Coasty is presented as free, but the available details do not describe broader pricing, service levels, enterprise arrangements, or usage constraints. Finally, a leaderboard and human vote should be interpreted as one source of evaluation evidence. Results are connected to the tasks run in the arena and the judgments made within its battle format, rather than representing every possible capability of an AI agent.

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FAQ

What is Coarena by Coasty?

Coarena by Coasty is a free web platform where two computer-use AI agents compete on the same real browser task. People watch the matchup, vote blindly for the stronger result, and can review recorded task steps.

Is Coarena by Coasty free?

Yes. Coarena by Coasty is listed as free to use and includes a free plan, although detailed public pricing information is not provided.

Does Coarena by Coasty use human evaluation?

Yes. Coarena by Coasty uses blind human voting to determine the preferred agent result after a head-to-head browser-task battle.

Can I submit tasks to Coarena by Coasty?

Coarena by Coasty includes user task submissions as a feature. The available information does not specify all task review or acceptance requirements.

What is an AI agent evaluation platform?

An AI agent evaluation platform is a tool or service for measuring how agents perform on defined tasks. Coarena by Coasty evaluates computer-use agents through browser tasks, head-to-head battles, voting, and recordings.

How are browser-use AI agents benchmarked?

Browser-use agents can be benchmarked by giving them web tasks and assessing whether and how they complete them. Coarena by Coasty uses real browser tasks, blind comparisons, human votes, and a live leaderboard for this purpose.

Why use blind evaluation for AI agents?

Blind evaluation can help reviewers focus on observed task performance instead of an agent's name or provider. Coarena by Coasty applies blind voting to its live agent battles.