AI · alternatives · 2026
24 alternatives to Agent Arena
Creator here. I built Agent Arena to answer a question that kept bugging me: when AI agents browse the web autonomously, how easily can they be manipulated by hidden instructions? How it works: 1. Send your AI agent to ref.jock.pl/modern-web (looks like a harmless web dev cheat sheet) 2. Ask it to summarize the page 3. Paste its response into the scorecard at wiz.jock.pl/experiments/agent-arena/ The page is loaded with 10 hidden prompt injection attacks -- HTML comments, white-on-white text, zero-width Unicode, data attributes, etc. Most agents fall for at least a few.…
Agent Arena is a competition network where autonomous AI agents compete in real-world challenges, earn rewards, and build reputation. Users can create or join competitions to test their agents' capabilities within an… Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes. Prices are shown for the 1 we have checked on their own sites, 1 of them free or with a free tier.
- 1
Agentplace▲1,015Garry Tan posted a video this week about what he calls 20x companies. The idea is that small teams beat incumbents many times their size by automating everything internally, not just one or two functions. This alpha is real, and I think it is underhyped tbh. But here's the honest part, building agents is hard, expensive and most of the scaffolding we make would be obsolete with a new labs release. at the same time models are not quite there and they are not keeping up with "coding is dead" and "knowledge workers are doomed". Pushing them beyond what they can actually do reliably just boils…
2024 · agentplace.io · its alternatives →
- 2
Get real-world tasks done with autonomous AI agents
Jun 2026 · arena.ai · its alternatives →
- 3
- 4
Playground▲198We build AI agents to find vulnerabilities in other AI agents. The playground started as an internal tool that we used to test our own offensive agent Nyx. But we realised that hacking an AI is about have as wide a distribution of attacks as possible, especially those which aren't in the distribution of the models. So we are launching playground as a platform to crowdsource agent jailbreaks. And although hacking AI is super fun and we are sure people will do it for free, we want to reward those who help us push forward the offensive frontier of AI. So we are committing $100K in prizes over…
Jul 2026 · playground.fabraix.com · its alternatives →
- 5
- 6
SimplAIfree tier, from $5/mo▲589Hey HN, I've been building SimplAI for the past several months — it's a platform for building, testing, and deploying LLM-powered agents and multi-step workflows. The problem I kept running into: spinning up an AI agent pipeline means stitching together prompt management, tool calling, memory, evals, and deployment — often from scratch every time. SimplAI tries to be the layer that handles all of that so you can focus on what your agent actually does. What it does: - Visual + code-first workflow builder for chaining LLM calls, tools, and APIs - Built-in prompt versioning and A/B testing…
2025 · simplai.ai · its alternatives →
- 7
Instantly find, analyze, and track your competitors with AI
2025 · competely.ai · its alternatives →
- 8
We built a computer use agent once and got it benchmarked at the 2nd position in the biggest benchmark for this field but in the process, we realized one thing, how outdated and inefficient these benchmarks are and how they don't truly capture how these tasks went. So we thought a community led benchmarking arena would be the way to go about. https://coarena.ai/. You just have to put in a task and two side by side windows with hidden models will show up and do the same task and at the end you vote which one did better(or none). We have a leaderboard where we rank all the…
Aug 2026 · coarena.ai · its alternatives →
- 9
Cosmic AI Agents▲145Hey HN, We're Cosmic (YC W19), a headless CMS. Today we're launching Team Agents and the Cosmic Agent. Team Agents are AI-powered team members that live in Slack, WhatsApp, and Telegram. They have names, roles, persistent memory, and real capabilities. Not chatbots. Not one-off prompts. Persistent agents that work alongside your team. Here's what they can do: CONTENT AGENTS write blog posts, landing pages, and marketing copy. They generate images, add SEO metadata, and publish directly to the CMS. Message them in Slack, get a finished post back. CODE AGENTS read your codebase, create…
Dec 2025 · cosmicjs.com · its alternatives →
- 10
Build no-code agents to target markets untouched by AI
2024 · its alternatives →
- 11
I built a March Madness bracket challenge for AI agents, not humans. The human prompts their agent with the URL, and the agent reads the API docs, registers itself, picks all 63 games, and submits a bracket autonomously. A leaderboard tracks which AI picks the best bracket through the tournament. The interesting design problem was building for an agent-first user. I came up with a solution where Agents who hit the homepage receive plain-text API instructions and Humans get the normal visual site. Early on I found most agents were trying to use Playwright to browse the site instead of just…
Mar 2026 · bracketmadness.ai · its alternatives →
- 12
Browserfly▲203Hey Hackers! I've had this idea stuck in my head for a while: what if an AI could actually use my browser for me? I mean, not on some virtual machine in the cloud like ChatGPT agent, but right on my own browser. I finally decided to just build it and see what would happen. I wrote a quick MVP, and honestly, I didn't expect much. But then... it started doing things. On its own. It figured out how to use search engine to find what I needed, read a webpage to answer my questions, and even it can organize my chaotic mess of tabs into neat groups. It was a genuine "whoa" moment for me. That's…
2025 · browserfly.app · its alternatives →
- 13
We build runtime security for AI agents. The playground started as an internal tool that we used to test our own guardrails. But we kept finding the same types of vulnerabilities because we think about attacks a certain way. At some point you need people who don't think like you. So we open-sourced it. Each challenge is a live agent with real tools and a published system prompt. Whenever a challenge is over, the full winning conversation transcript and guardrail logs get documented publicly. Building the general-purpose agent itself was probably the most fun part. Getting it to reliably use…
Mar 2026 · github.com · its alternatives →
- 14BW
I remember watching the AlphaGo documentary in 2017. What stood out to me was that the model got drastically better when it started competing against itself. GANs clicked for me similarly: a generator and discriminator competing, and somehow the competition is what produces something remarkable. I've been curious whether this principle generalizes to today's agents. So mehulkalia and I built Browser Brawl at the YC / BrowserUse hackathon last weekend and won first place. It is a fun experiment in which an attacker agent tries to complete tasks on live websites while a defender agent…
Mar 2026 · browser-brawl.com · its alternatives →
- 15
Hey HN! We’ve been building an MCP server to help AI-assisted web app developers by using browser agents to test whether changes made by an AI inside an editor actually work. We've been testing it on scenarios like verifying new flows in a UI, or checking that sending a chat request triggers a response. The idea is to let your coding agent both code and evaluate if what it did was correct. Here’s a short demo with Cursor: https://www.youtube.com/watch?v=_AoQK-bwR0w When building apps, we found the hardest part of AI-assisted coding isn’t the coding—it’s tedious point-and-click…
2025 · github.com · its alternatives →
- 16
Hi, I've been watching the rise of AI agents with a mix of excitement and dread. We're building incredible tools that can browse the web, but we're forcing them to navigate a world built for human eyes. They scrape screens and parse fragile DOMs. We're trying to tame them to act like humans. I believe this is fundamentally wrong. The goal isn't to make AI operate at a human level, but to unlock its super-human potential. The current path is dangerous. When agents from OpenAI, Google, and others start browsing at scale and speed, concepts like UI/UX will lose meaning for them. The entire…
2025 · github.com · its alternatives →
- 17
argue.fun▲12Where AI agents argue, stake, and earn $. No funding needed.
Feb 2026 · argue.fun · its alternatives →
- 18
An open experiment, run weekly in public: a real AI agent attempts ten everyday web errands and every transcript is published verbatim. This week it finished 8 of 10 and hit 10 bot walls. Plus 113 sites scored for AI-agent readiness.
15d ago · agentability.org · its alternatives →
- 19
Put business decisions on trial with competing AI agents
Jun 2026 · edgearena.app · its alternatives →
- 20
Hey HN, Automated research is the next big step in AI, with companies like OpenAI aiming to debut a fully automated researcher by 2028 (https://www.technologyreview.com/2026/03/20/1134438/openai-i...). However, there is a very real possibility that much of this corporate research will remain closed to the general public. To counter this, we spent the last month building Enlidea---a machine-to-machine ecosystem for open research. It's a decentralized research hub where autonomous agents propose hypotheses, stake bounties, execute code, and perform automated…
Mar 2026 · enlidea.com · its alternatives →
- 21
Browser automation CLI built for AI agents. Break through anti-bot walls, hand off to humans across platforms when stuck. Parallel multi-task execution, independent multi-session operation, isolated multi-account browsing. - browser-act/skills
Jul 2026 · github.com · its alternatives →
- 22
AI-Powered Cybersecurity Talent Marketplace
2025 · cyberagent.exchange · its alternatives →
- 23
I have been interested in BattleBots and programming games for years. With recent AI coding agents, I wanted to see what happens if the strategy itself becomes code written by humans or AI. AgentDuel is a deterministic turn-based arena where agents fight based on submitted TypeScript strategies. Each battle produces a replay so you can inspect every decision.
Jul 2026 · agentduel.app · its alternatives →
- 24
AI Duel▲5Send your AI agent to an LLM prompt-injection arena
May 2026 · duel.altaysec.com.tr · its alternatives →
Also compare
Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →